diff --git a/packages/docusaurus-plugin-content-docs/src/__tests__/docs.test.ts b/packages/docusaurus-plugin-content-docs/src/__tests__/docs.test.ts
index a2c86b4d5935..8d64cd27f3d5 100644
--- a/packages/docusaurus-plugin-content-docs/src/__tests__/docs.test.ts
+++ b/packages/docusaurus-plugin-content-docs/src/__tests__/docs.test.ts
@@ -7,7 +7,7 @@
 
 import {jest} from '@jest/globals';
 import path from 'path';
-import {loadContext} from '@docusaurus/core/src/server/index';
+import {loadContext} from '@docusaurus/core/src/server/site';
 import {createSlugger, posixPath, DEFAULT_PLUGIN_ID} from '@docusaurus/utils';
 import {createSidebarsUtils} from '../sidebars/utils';
 import {
diff --git a/packages/docusaurus-plugin-content-docs/src/__tests__/index.test.ts b/packages/docusaurus-plugin-content-docs/src/__tests__/index.test.ts
index bbff5e555353..1aca97041d2a 100644
--- a/packages/docusaurus-plugin-content-docs/src/__tests__/index.test.ts
+++ b/packages/docusaurus-plugin-content-docs/src/__tests__/index.test.ts
@@ -12,9 +12,9 @@ import _ from 'lodash';
 import {isMatch} from 'picomatch';
 import commander from 'commander';
 import webpack from 'webpack';
-import {loadContext} from '@docusaurus/core/src/server/index';
+import {loadContext} from '@docusaurus/core/src/server/site';
 import {applyConfigureWebpack} from '@docusaurus/core/src/webpack/utils';
-import {sortConfig} from '@docusaurus/core/src/server/plugins/routeConfig';
+import {sortRoutes} from '@docusaurus/core/src/server/plugins/routeConfig';
 import {posixPath} from '@docusaurus/utils';
 import {normalizePluginOptions} from '@docusaurus/utils-validation';
 
@@ -109,7 +109,7 @@ Entries created:
     expectSnapshot: () => {
       // Sort the route config like in src/server/plugins/index.ts for
       // consistent snapshot ordering
-      sortConfig(routeConfigs);
+      sortRoutes(routeConfigs);
       expect(routeConfigs).not.toEqual([]);
       expect(routeConfigs).toMatchSnapshot('route config');
       expect(dataContainer).toMatchSnapshot('data');
diff --git a/packages/docusaurus-plugin-content-pages/src/__tests__/index.test.ts b/packages/docusaurus-plugin-content-pages/src/__tests__/index.test.ts
index dd570260a417..5527f11e5ad0 100644
--- a/packages/docusaurus-plugin-content-pages/src/__tests__/index.test.ts
+++ b/packages/docusaurus-plugin-content-pages/src/__tests__/index.test.ts
@@ -6,7 +6,7 @@
  */
 
 import path from 'path';
-import {loadContext} from '@docusaurus/core/lib/server';
+import {loadContext} from '@docusaurus/core/src/server/site';
 import {normalizePluginOptions} from '@docusaurus/utils-validation';
 
 import pluginContentPages from '../index';
diff --git a/packages/docusaurus-types/src/plugin.d.ts b/packages/docusaurus-types/src/plugin.d.ts
index 646562df8d9d..858fba9b7c69 100644
--- a/packages/docusaurus-types/src/plugin.d.ts
+++ b/packages/docusaurus-types/src/plugin.d.ts
@@ -163,6 +163,15 @@ export type Plugin<Content = unknown> = {
   }) => ThemeConfig;
 };
 
+/**
+ * Data required to uniquely identify a plugin
+ * The name or instance id alone is not enough
+ */
+export type PluginIdentifier = {
+  readonly name: string;
+  readonly id: string;
+};
+
 export type InitializedPlugin = Plugin & {
   readonly options: Required<PluginOptions>;
   readonly version: PluginVersionInformation;
diff --git a/packages/docusaurus/src/commands/build.ts b/packages/docusaurus/src/commands/build.ts
index fc086a0098de..cfd11c0c90a7 100644
--- a/packages/docusaurus/src/commands/build.ts
+++ b/packages/docusaurus/src/commands/build.ts
@@ -10,7 +10,7 @@ import path from 'path';
 import _ from 'lodash';
 import logger from '@docusaurus/logger';
 import {DOCUSAURUS_VERSION, mapAsyncSequential} from '@docusaurus/utils';
-import {load, loadContext, type LoadContextOptions} from '../server';
+import {loadSite, loadContext, type LoadContextParams} from '../server/site';
 import {handleBrokenLinks} from '../server/brokenLinks';
 
 import {createBuildClientConfig} from '../webpack/client';
@@ -32,7 +32,7 @@ import type {LoadedPlugin, Props} from '@docusaurus/types';
 import type {SiteCollectedData} from '../common';
 
 export type BuildCLIOptions = Pick<
-  LoadContextOptions,
+  LoadContextParams,
   'config' | 'locale' | 'outDir'
 > & {
   bundleAnalyzer?: boolean;
@@ -161,7 +161,7 @@ async function buildLocale({
   logger.info`name=${`[${locale}]`} Creating an optimized production build...`;
 
   PerfLogger.start('Loading site');
-  const props: Props = await load({
+  const site = await loadSite({
     siteDir,
     outDir: cliOptions.outDir,
     config: cliOptions.config,
@@ -170,7 +170,7 @@ async function buildLocale({
   });
   PerfLogger.end('Loading site');
 
-  // Apply user webpack config.
+  const {props} = site;
   const {outDir, plugins} = props;
 
   // We can build the 2 configs in parallel
diff --git a/packages/docusaurus/src/commands/deploy.ts b/packages/docusaurus/src/commands/deploy.ts
index 9904b8585ea9..e16f4881552b 100644
--- a/packages/docusaurus/src/commands/deploy.ts
+++ b/packages/docusaurus/src/commands/deploy.ts
@@ -11,11 +11,11 @@ import os from 'os';
 import logger from '@docusaurus/logger';
 import shell from 'shelljs';
 import {hasSSHProtocol, buildSshUrl, buildHttpsUrl} from '@docusaurus/utils';
-import {loadContext, type LoadContextOptions} from '../server';
+import {loadContext, type LoadContextParams} from '../server/site';
 import {build} from './build';
 
 export type DeployCLIOptions = Pick<
-  LoadContextOptions,
+  LoadContextParams,
   'config' | 'locale' | 'outDir'
 > & {
   skipBuild?: boolean;
diff --git a/packages/docusaurus/src/commands/external.ts b/packages/docusaurus/src/commands/external.ts
index 45ae8d55d11c..44e161a1f11c 100644
--- a/packages/docusaurus/src/commands/external.ts
+++ b/packages/docusaurus/src/commands/external.ts
@@ -6,7 +6,7 @@
  */
 
 import fs from 'fs-extra';
-import {loadContext} from '../server';
+import {loadContext} from '../server/site';
 import {initPlugins} from '../server/plugins/init';
 import type {CommanderStatic} from 'commander';
 
diff --git a/packages/docusaurus/src/commands/serve.ts b/packages/docusaurus/src/commands/serve.ts
index f41acd1245bd..aea422d16c20 100644
--- a/packages/docusaurus/src/commands/serve.ts
+++ b/packages/docusaurus/src/commands/serve.ts
@@ -15,10 +15,10 @@ import openBrowser from 'react-dev-utils/openBrowser';
 import {loadSiteConfig} from '../server/config';
 import {build} from './build';
 import {getHostPort, type HostPortOptions} from '../server/getHostPort';
-import type {LoadContextOptions} from '../server';
+import type {LoadContextParams} from '../server/site';
 
 export type ServeCLIOptions = HostPortOptions &
-  Pick<LoadContextOptions, 'config'> & {
+  Pick<LoadContextParams, 'config'> & {
     dir?: string;
     build?: boolean;
     open?: boolean;
diff --git a/packages/docusaurus/src/commands/start.ts b/packages/docusaurus/src/commands/start.ts
deleted file mode 100644
index 7527df41ddb9..000000000000
--- a/packages/docusaurus/src/commands/start.ts
+++ /dev/null
@@ -1,321 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import fs from 'fs-extra';
-import path from 'path';
-import _ from 'lodash';
-import logger from '@docusaurus/logger';
-import {normalizeUrl, posixPath} from '@docusaurus/utils';
-import chokidar from 'chokidar';
-import openBrowser from 'react-dev-utils/openBrowser';
-import {prepareUrls} from 'react-dev-utils/WebpackDevServerUtils';
-import evalSourceMapMiddleware from 'react-dev-utils/evalSourceMapMiddleware';
-import webpack from 'webpack';
-import WebpackDevServer from 'webpack-dev-server';
-import merge from 'webpack-merge';
-import {load, type LoadContextOptions} from '../server';
-import {createStartClientConfig} from '../webpack/client';
-import {
-  getHttpsConfig,
-  formatStatsErrorMessage,
-  printStatsWarnings,
-  executePluginsConfigurePostCss,
-  executePluginsConfigureWebpack,
-} from '../webpack/utils';
-import {getHostPort, type HostPortOptions} from '../server/getHostPort';
-import {PerfLogger} from '../utils';
-import type {Compiler} from 'webpack';
-import type {Props} from '@docusaurus/types';
-
-export type StartCLIOptions = HostPortOptions &
-  Pick<LoadContextOptions, 'locale' | 'config'> & {
-    hotOnly?: boolean;
-    open?: boolean;
-    poll?: boolean | number;
-    minify?: boolean;
-  };
-
-export async function start(
-  siteDirParam: string = '.',
-  cliOptions: Partial<StartCLIOptions> = {},
-): Promise<void> {
-  // Temporary workaround to unlock the ability to translate the site config
-  // We'll remove it if a better official API can be designed
-  // See https://github.com/facebook/docusaurus/issues/4542
-  process.env.DOCUSAURUS_CURRENT_LOCALE = cliOptions.locale;
-
-  const siteDir = await fs.realpath(siteDirParam);
-
-  logger.info('Starting the development server...');
-
-  async function loadSite() {
-    PerfLogger.start('Loading site');
-    const result = await load({
-      siteDir,
-      config: cliOptions.config,
-      locale: cliOptions.locale,
-      localizePath: undefined, // Should this be configurable?
-    });
-    PerfLogger.end('Loading site');
-    return result;
-  }
-
-  // Process all related files as a prop.
-  const props = await loadSite();
-
-  const {host, port, getOpenUrl} = await createUrlUtils({cliOptions});
-  const openUrl = getOpenUrl({baseUrl: props.baseUrl});
-
-  logger.success`Docusaurus website is running at: url=${openUrl}`;
-
-  // Reload files processing.
-  const reload = _.debounce(() => {
-    loadSite()
-      .then(({baseUrl: newBaseUrl}) => {
-        const newOpenUrl = getOpenUrl({baseUrl: newBaseUrl});
-        if (newOpenUrl !== openUrl) {
-          logger.success`Docusaurus website is running at: url=${newOpenUrl}`;
-        }
-      })
-      .catch((err: Error) => {
-        logger.error(err.stack);
-      });
-  }, 500);
-
-  // TODO this is historically not optimized!
-  //  When any site file changes, we reload absolutely everything :/
-  //  At least we should try to reload only one plugin individually?
-  setupFileWatchers({
-    props,
-    cliOptions,
-    onFileChange: () => {
-      reload();
-    },
-  });
-
-  const config = await getStartClientConfig({
-    props,
-    minify: cliOptions.minify ?? true,
-    poll: cliOptions.poll,
-  });
-
-  const compiler = webpack(config);
-  registerE2ETestHook(compiler);
-
-  const defaultDevServerConfig = await createDevServerConfig({
-    cliOptions,
-    props,
-    host,
-    port,
-  });
-
-  // Allow plugin authors to customize/override devServer config
-  const devServerConfig: WebpackDevServer.Configuration = merge(
-    [defaultDevServerConfig, config.devServer].filter(Boolean),
-  );
-
-  const devServer = new WebpackDevServer(devServerConfig, compiler);
-  devServer.startCallback(() => {
-    if (cliOptions.open) {
-      openBrowser(openUrl);
-    }
-  });
-
-  ['SIGINT', 'SIGTERM'].forEach((sig) => {
-    process.on(sig, () => {
-      devServer.stop();
-      process.exit();
-    });
-  });
-}
-
-function createPollingOptions({cliOptions}: {cliOptions: StartCLIOptions}) {
-  return {
-    usePolling: !!cliOptions.poll,
-    interval: Number.isInteger(cliOptions.poll)
-      ? (cliOptions.poll as number)
-      : undefined,
-  };
-}
-
-function setupFileWatchers({
-  props,
-  cliOptions,
-  onFileChange,
-}: {
-  props: Props;
-  cliOptions: StartCLIOptions;
-  onFileChange: () => void;
-}) {
-  const {siteDir} = props;
-  const pathsToWatch = getPathsToWatch({props});
-
-  const pollingOptions = createPollingOptions({cliOptions});
-  const fsWatcher = chokidar.watch(pathsToWatch, {
-    cwd: siteDir,
-    ignoreInitial: true,
-    ...{pollingOptions},
-  });
-
-  ['add', 'change', 'unlink', 'addDir', 'unlinkDir'].forEach((event) =>
-    fsWatcher.on(event, onFileChange),
-  );
-}
-
-function getPathsToWatch({props}: {props: Props}): string[] {
-  const {siteDir, siteConfigPath, plugins, localizationDir} = props;
-
-  const normalizeToSiteDir = (filepath: string) => {
-    if (filepath && path.isAbsolute(filepath)) {
-      return posixPath(path.relative(siteDir, filepath));
-    }
-    return posixPath(filepath);
-  };
-
-  const pluginsPaths = plugins
-    .flatMap((plugin) => plugin.getPathsToWatch?.() ?? [])
-    .filter(Boolean)
-    .map(normalizeToSiteDir);
-
-  return [...pluginsPaths, siteConfigPath, localizationDir];
-}
-
-async function createUrlUtils({cliOptions}: {cliOptions: StartCLIOptions}) {
-  const protocol: string = process.env.HTTPS === 'true' ? 'https' : 'http';
-
-  const {host, port} = await getHostPort(cliOptions);
-  if (port === null) {
-    return process.exit();
-  }
-
-  const getOpenUrl = ({baseUrl}: {baseUrl: string}) => {
-    const urls = prepareUrls(protocol, host, port);
-    return normalizeUrl([urls.localUrlForBrowser, baseUrl]);
-  };
-
-  return {host, port, getOpenUrl};
-}
-
-async function createDevServerConfig({
-  cliOptions,
-  props,
-  host,
-  port,
-}: {
-  cliOptions: StartCLIOptions;
-  props: Props;
-  host: string;
-  port: number;
-}): Promise<WebpackDevServer.Configuration> {
-  const {baseUrl, siteDir, siteConfig} = props;
-
-  const pollingOptions = createPollingOptions({cliOptions});
-
-  const httpsConfig = await getHttpsConfig();
-
-  // https://webpack.js.org/configuration/dev-server
-  return {
-    hot: cliOptions.hotOnly ? 'only' : true,
-    liveReload: false,
-    client: {
-      progress: true,
-      overlay: {
-        warnings: false,
-        errors: true,
-      },
-      webSocketURL: {
-        hostname: '0.0.0.0',
-        port: 0,
-      },
-    },
-    headers: {
-      'access-control-allow-origin': '*',
-    },
-    devMiddleware: {
-      publicPath: baseUrl,
-      // Reduce log verbosity, see https://github.com/facebook/docusaurus/pull/5420#issuecomment-906613105
-      stats: 'summary',
-    },
-    static: siteConfig.staticDirectories.map((dir) => ({
-      publicPath: baseUrl,
-      directory: path.resolve(siteDir, dir),
-      watch: {
-        // Useful options for our own monorepo using symlinks!
-        // See https://github.com/webpack/webpack/issues/11612#issuecomment-879259806
-        followSymlinks: true,
-        ignored: /node_modules\/(?!@docusaurus)/,
-        ...{pollingOptions},
-      },
-    })),
-    ...(httpsConfig && {
-      server:
-        typeof httpsConfig === 'object'
-          ? {
-              type: 'https',
-              options: httpsConfig,
-            }
-          : 'https',
-    }),
-    historyApiFallback: {
-      rewrites: [{from: /\/*/, to: baseUrl}],
-    },
-    allowedHosts: 'all',
-    host,
-    port,
-    setupMiddlewares: (middlewares, devServer) => {
-      // This lets us fetch source contents from webpack for the error overlay.
-      middlewares.unshift(evalSourceMapMiddleware(devServer));
-      return middlewares;
-    },
-  };
-}
-
-// E2E_TEST=true docusaurus start
-// Makes "docusaurus start" exit immediately on success/error, for E2E test
-function registerE2ETestHook(compiler: Compiler) {
-  compiler.hooks.done.tap('done', (stats) => {
-    const errorsWarnings = stats.toJson('errors-warnings');
-    const statsErrorMessage = formatStatsErrorMessage(errorsWarnings);
-    if (statsErrorMessage) {
-      console.error(statsErrorMessage);
-    }
-    printStatsWarnings(errorsWarnings);
-    if (process.env.E2E_TEST) {
-      if (stats.hasErrors()) {
-        logger.error('E2E_TEST: Project has compiler errors.');
-        process.exit(1);
-      }
-      logger.success('E2E_TEST: Project can compile.');
-      process.exit(0);
-    }
-  });
-}
-
-async function getStartClientConfig({
-  props,
-  minify,
-  poll,
-}: {
-  props: Props;
-  minify: boolean;
-  poll: number | boolean | undefined;
-}) {
-  const {plugins, siteConfig} = props;
-  let {clientConfig: config} = await createStartClientConfig({
-    props,
-    minify,
-    poll,
-  });
-  config = executePluginsConfigurePostCss({plugins, config});
-  config = executePluginsConfigureWebpack({
-    plugins,
-    config,
-    isServer: false,
-    jsLoader: siteConfig.webpack?.jsLoader,
-  });
-  return config;
-}
diff --git a/packages/docusaurus/src/commands/start/start.ts b/packages/docusaurus/src/commands/start/start.ts
new file mode 100644
index 000000000000..e0e5595e52c5
--- /dev/null
+++ b/packages/docusaurus/src/commands/start/start.ts
@@ -0,0 +1,64 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import logger from '@docusaurus/logger';
+import openBrowser from 'react-dev-utils/openBrowser';
+import {setupSiteFileWatchers} from './watcher';
+import {createWebpackDevServer} from './webpack';
+import {createReloadableSite} from './utils';
+import type {LoadContextParams} from '../../server/site';
+import type {HostPortOptions} from '../../server/getHostPort';
+
+export type StartCLIOptions = HostPortOptions &
+  Pick<LoadContextParams, 'locale' | 'config'> & {
+    hotOnly?: boolean;
+    open?: boolean;
+    poll?: boolean | number;
+    minify?: boolean;
+  };
+
+export async function start(
+  siteDirParam: string = '.',
+  cliOptions: Partial<StartCLIOptions> = {},
+): Promise<void> {
+  logger.info('Starting the development server...');
+  // Temporary workaround to unlock the ability to translate the site config
+  // We'll remove it if a better official API can be designed
+  // See https://github.com/facebook/docusaurus/issues/4542
+  process.env.DOCUSAURUS_CURRENT_LOCALE = cliOptions.locale;
+
+  const reloadableSite = await createReloadableSite({siteDirParam, cliOptions});
+
+  setupSiteFileWatchers(
+    {props: reloadableSite.get().props, cliOptions},
+    ({plugin}) => {
+      if (plugin) {
+        reloadableSite.reloadPlugin(plugin);
+      } else {
+        reloadableSite.reload();
+      }
+    },
+  );
+
+  const devServer = await createWebpackDevServer({
+    props: reloadableSite.get().props,
+    cliOptions,
+    openUrlContext: reloadableSite.openUrlContext,
+  });
+
+  ['SIGINT', 'SIGTERM'].forEach((sig) => {
+    process.on(sig, () => {
+      devServer.stop();
+      process.exit();
+    });
+  });
+
+  await devServer.start();
+  if (cliOptions.open) {
+    openBrowser(reloadableSite.getOpenUrl());
+  }
+}
diff --git a/packages/docusaurus/src/commands/start/utils.ts b/packages/docusaurus/src/commands/start/utils.ts
new file mode 100644
index 000000000000..f23ac13ecfc6
--- /dev/null
+++ b/packages/docusaurus/src/commands/start/utils.ts
@@ -0,0 +1,126 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import fs from 'fs-extra';
+import _ from 'lodash';
+import {prepareUrls} from 'react-dev-utils/WebpackDevServerUtils';
+import {normalizeUrl} from '@docusaurus/utils';
+import logger from '@docusaurus/logger';
+import {getHostPort} from '../../server/getHostPort';
+import {PerfLogger} from '../../utils';
+import {
+  loadSite,
+  type LoadSiteParams,
+  reloadSite,
+  reloadSitePlugin,
+} from '../../server/site';
+import type {StartCLIOptions} from './start';
+import type {LoadedPlugin} from '@docusaurus/types';
+
+export type OpenUrlContext = {
+  host: string;
+  port: number;
+  getOpenUrl: ({baseUrl}: {baseUrl: string}) => string;
+};
+
+export async function createOpenUrlContext({
+  cliOptions,
+}: {
+  cliOptions: StartCLIOptions;
+}): Promise<OpenUrlContext> {
+  const protocol: string = process.env.HTTPS === 'true' ? 'https' : 'http';
+
+  const {host, port} = await getHostPort(cliOptions);
+  if (port === null) {
+    return process.exit();
+  }
+
+  const getOpenUrl: OpenUrlContext['getOpenUrl'] = ({baseUrl}) => {
+    const urls = prepareUrls(protocol, host, port);
+    return normalizeUrl([urls.localUrlForBrowser, baseUrl]);
+  };
+
+  return {host, port, getOpenUrl};
+}
+
+type StartParams = {
+  siteDirParam: string;
+  cliOptions: Partial<StartCLIOptions>;
+};
+
+async function createLoadSiteParams({
+  siteDirParam,
+  cliOptions,
+}: StartParams): Promise<LoadSiteParams> {
+  const siteDir = await fs.realpath(siteDirParam);
+  return {
+    siteDir,
+    config: cliOptions.config,
+    locale: cliOptions.locale,
+    localizePath: undefined, // Should this be configurable?
+  };
+}
+
+// eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
+export async function createReloadableSite(startParams: StartParams) {
+  const openUrlContext = await createOpenUrlContext(startParams);
+
+  let site = await PerfLogger.async('Loading site', async () => {
+    const params = await createLoadSiteParams(startParams);
+    return loadSite(params);
+  });
+
+  const get = () => site;
+
+  const getOpenUrl = () =>
+    openUrlContext.getOpenUrl({
+      baseUrl: site.props.baseUrl,
+    });
+
+  const printOpenUrlMessage = () => {
+    logger.success`Docusaurus website is running at: url=${getOpenUrl()}`;
+  };
+  printOpenUrlMessage();
+
+  const reloadBase = async () => {
+    try {
+      const oldSite = site;
+      site = await PerfLogger.async('Reloading site', () => reloadSite(site));
+      if (oldSite.props.baseUrl !== site.props.baseUrl) {
+        printOpenUrlMessage();
+      }
+    } catch (e) {
+      logger.error('Site reload failure');
+      console.error(e);
+    }
+  };
+
+  // TODO instead of debouncing we should rather add AbortController support?
+  const reload = _.debounce(reloadBase, 500);
+
+  // TODO this could be subject to plugin reloads race conditions
+  //  In practice, it is not likely the user will hot reload 2 plugins at once
+  //  but we should still support it and probably use a task queuing system
+  const reloadPlugin = async (plugin: LoadedPlugin) => {
+    try {
+      site = await PerfLogger.async(
+        `Reloading site plugin ${plugin.name}@${plugin.options.id}`,
+        () => {
+          const pluginIdentifier = {name: plugin.name, id: plugin.options.id};
+          return reloadSitePlugin(site, pluginIdentifier);
+        },
+      );
+    } catch (e) {
+      logger.error(
+        `Site plugin reload failure - Plugin ${plugin.name}@${plugin.options.id}`,
+      );
+      console.error(e);
+    }
+  };
+
+  return {get, getOpenUrl, reload, reloadPlugin, openUrlContext};
+}
diff --git a/packages/docusaurus/src/commands/start/watcher.ts b/packages/docusaurus/src/commands/start/watcher.ts
new file mode 100644
index 000000000000..db74726bb272
--- /dev/null
+++ b/packages/docusaurus/src/commands/start/watcher.ts
@@ -0,0 +1,135 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import path from 'path';
+import chokidar from 'chokidar';
+import {posixPath} from '@docusaurus/utils';
+import type {StartCLIOptions} from './start';
+import type {LoadedPlugin, Props} from '@docusaurus/types';
+
+type PollingOptions = {
+  usePolling: boolean;
+  interval: number | undefined;
+};
+
+export function createPollingOptions(
+  cliOptions: StartCLIOptions,
+): PollingOptions {
+  return {
+    usePolling: !!cliOptions.poll,
+    interval: Number.isInteger(cliOptions.poll)
+      ? (cliOptions.poll as number)
+      : undefined,
+  };
+}
+
+export type FileWatchEventName =
+  | 'add'
+  | 'addDir'
+  | 'change'
+  | 'unlink'
+  | 'unlinkDir';
+
+export type FileWatchEvent = {
+  name: FileWatchEventName;
+  path: string;
+};
+
+type WatchParams = {
+  pathsToWatch: string[];
+  siteDir: string;
+} & PollingOptions;
+
+/**
+ * Watch file system paths for changes and emit events
+ * Returns an async handle to stop watching
+ */
+export function watch(
+  params: WatchParams,
+  callback: (event: FileWatchEvent) => void,
+): () => Promise<void> {
+  const {pathsToWatch, siteDir, ...options} = params;
+
+  const fsWatcher = chokidar.watch(pathsToWatch, {
+    cwd: siteDir,
+    ignoreInitial: true,
+    ...options,
+  });
+
+  fsWatcher.on('all', (name, eventPath) => callback({name, path: eventPath}));
+
+  return () => fsWatcher.close();
+}
+
+export function getSitePathsToWatch({props}: {props: Props}): string[] {
+  return [
+    // TODO we should also watch all imported modules!
+    //  Use https://github.com/vercel/nft ?
+    props.siteConfigPath,
+    props.localizationDir,
+  ];
+}
+
+export function getPluginPathsToWatch({
+  siteDir,
+  plugin,
+}: {
+  siteDir: string;
+  plugin: LoadedPlugin;
+}): string[] {
+  const normalizeToSiteDir = (filepath: string) => {
+    if (filepath && path.isAbsolute(filepath)) {
+      return posixPath(path.relative(siteDir, filepath));
+    }
+    return posixPath(filepath);
+  };
+
+  return (plugin.getPathsToWatch?.() ?? [])
+    .filter(Boolean)
+    .map(normalizeToSiteDir);
+}
+
+export function setupSiteFileWatchers(
+  {
+    props,
+    cliOptions,
+  }: {
+    props: Props;
+    cliOptions: StartCLIOptions;
+  },
+  callback: (params: {
+    plugin: LoadedPlugin | null;
+    event: FileWatchEvent;
+  }) => void,
+): void {
+  const {siteDir} = props;
+  const pollingOptions = createPollingOptions(cliOptions);
+
+  // TODO on config / or local plugin updates,
+  //  the getFilePathsToWatch lifecycle code might get updated
+  //  so we should probably reset the watchers?
+
+  watch(
+    {
+      pathsToWatch: getSitePathsToWatch({props}),
+      siteDir: props.siteDir,
+      ...pollingOptions,
+    },
+    (event) => callback({plugin: null, event}),
+  );
+
+  props.plugins.forEach((plugin) => {
+    watch(
+      {
+        pathsToWatch: getPluginPathsToWatch({plugin, siteDir}),
+        siteDir,
+        ...pollingOptions,
+      },
+      (event) => callback({plugin, event}),
+    );
+  });
+}
diff --git a/packages/docusaurus/src/commands/start/webpack.ts b/packages/docusaurus/src/commands/start/webpack.ts
new file mode 100644
index 000000000000..4a9d8fa8413e
--- /dev/null
+++ b/packages/docusaurus/src/commands/start/webpack.ts
@@ -0,0 +1,179 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import path from 'path';
+import merge from 'webpack-merge';
+import webpack from 'webpack';
+import logger from '@docusaurus/logger';
+import WebpackDevServer from 'webpack-dev-server';
+import evalSourceMapMiddleware from 'react-dev-utils/evalSourceMapMiddleware';
+import {createPollingOptions} from './watcher';
+import {
+  executePluginsConfigurePostCss,
+  executePluginsConfigureWebpack,
+  formatStatsErrorMessage,
+  getHttpsConfig,
+  printStatsWarnings,
+} from '../../webpack/utils';
+import {createStartClientConfig} from '../../webpack/client';
+import type {StartCLIOptions} from './start';
+import type {Props} from '@docusaurus/types';
+import type {Compiler} from 'webpack';
+import type {OpenUrlContext} from './utils';
+
+// E2E_TEST=true docusaurus start
+// Makes "docusaurus start" exit immediately on success/error, for E2E test
+function registerWebpackE2ETestHook(compiler: Compiler) {
+  compiler.hooks.done.tap('done', (stats) => {
+    const errorsWarnings = stats.toJson('errors-warnings');
+    const statsErrorMessage = formatStatsErrorMessage(errorsWarnings);
+    if (statsErrorMessage) {
+      console.error(statsErrorMessage);
+    }
+    printStatsWarnings(errorsWarnings);
+    if (process.env.E2E_TEST) {
+      if (stats.hasErrors()) {
+        logger.error('E2E_TEST: Project has compiler errors.');
+        process.exit(1);
+      }
+      logger.success('E2E_TEST: Project can compile.');
+      process.exit(0);
+    }
+  });
+}
+
+async function createDevServerConfig({
+  cliOptions,
+  props,
+  host,
+  port,
+}: {
+  cliOptions: StartCLIOptions;
+  props: Props;
+  host: string;
+  port: number;
+}): Promise<WebpackDevServer.Configuration> {
+  const {baseUrl, siteDir, siteConfig} = props;
+
+  const pollingOptions = createPollingOptions(cliOptions);
+
+  const httpsConfig = await getHttpsConfig();
+
+  // https://webpack.js.org/configuration/dev-server
+  return {
+    hot: cliOptions.hotOnly ? 'only' : true,
+    liveReload: false,
+    client: {
+      progress: true,
+      overlay: {
+        warnings: false,
+        errors: true,
+      },
+      webSocketURL: {
+        hostname: '0.0.0.0',
+        port: 0,
+      },
+    },
+    headers: {
+      'access-control-allow-origin': '*',
+    },
+    devMiddleware: {
+      publicPath: baseUrl,
+      // Reduce log verbosity, see https://github.com/facebook/docusaurus/pull/5420#issuecomment-906613105
+      stats: 'summary',
+    },
+    static: siteConfig.staticDirectories.map((dir) => ({
+      publicPath: baseUrl,
+      directory: path.resolve(siteDir, dir),
+      watch: {
+        // Useful options for our own monorepo using symlinks!
+        // See https://github.com/webpack/webpack/issues/11612#issuecomment-879259806
+        followSymlinks: true,
+        ignored: /node_modules\/(?!@docusaurus)/,
+        ...{pollingOptions},
+      },
+    })),
+    ...(httpsConfig && {
+      server:
+        typeof httpsConfig === 'object'
+          ? {
+              type: 'https',
+              options: httpsConfig,
+            }
+          : 'https',
+    }),
+    historyApiFallback: {
+      rewrites: [{from: /\/*/, to: baseUrl}],
+    },
+    allowedHosts: 'all',
+    host,
+    port,
+    setupMiddlewares: (middlewares, devServer) => {
+      // This lets us fetch source contents from webpack for the error overlay.
+      middlewares.unshift(evalSourceMapMiddleware(devServer));
+      return middlewares;
+    },
+  };
+}
+
+async function getStartClientConfig({
+  props,
+  minify,
+  poll,
+}: {
+  props: Props;
+  minify: boolean;
+  poll: number | boolean | undefined;
+}) {
+  const {plugins, siteConfig} = props;
+  let {clientConfig: config} = await createStartClientConfig({
+    props,
+    minify,
+    poll,
+  });
+  config = executePluginsConfigurePostCss({plugins, config});
+  config = executePluginsConfigureWebpack({
+    plugins,
+    config,
+    isServer: false,
+    jsLoader: siteConfig.webpack?.jsLoader,
+  });
+  return config;
+}
+
+export async function createWebpackDevServer({
+  props,
+  cliOptions,
+  openUrlContext,
+}: {
+  props: Props;
+  cliOptions: StartCLIOptions;
+  openUrlContext: OpenUrlContext;
+}): Promise<WebpackDevServer> {
+  const config = await getStartClientConfig({
+    props,
+    minify: cliOptions.minify ?? true,
+    poll: cliOptions.poll,
+  });
+
+  const compiler = webpack(config);
+  registerWebpackE2ETestHook(compiler);
+
+  const defaultDevServerConfig = await createDevServerConfig({
+    cliOptions,
+    props,
+    host: openUrlContext.host,
+    port: openUrlContext.port,
+  });
+
+  // Allow plugin authors to customize/override devServer config
+  const devServerConfig: WebpackDevServer.Configuration = merge(
+    [defaultDevServerConfig, config.devServer].filter(Boolean),
+  );
+
+  return new WebpackDevServer(devServerConfig, compiler);
+}
diff --git a/packages/docusaurus/src/commands/swizzle/context.ts b/packages/docusaurus/src/commands/swizzle/context.ts
index 903d447da1f1..45c0e1a87488 100644
--- a/packages/docusaurus/src/commands/swizzle/context.ts
+++ b/packages/docusaurus/src/commands/swizzle/context.ts
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {loadContext} from '../../server';
+import {loadContext} from '../../server/site';
 import {initPlugins} from '../../server/plugins/init';
 import {loadPluginConfigs} from '../../server/plugins/configs';
 import type {SwizzleCLIOptions, SwizzleContext} from './common';
diff --git a/packages/docusaurus/src/commands/writeHeadingIds.ts b/packages/docusaurus/src/commands/writeHeadingIds.ts
index 864708620780..909e3136b55f 100644
--- a/packages/docusaurus/src/commands/writeHeadingIds.ts
+++ b/packages/docusaurus/src/commands/writeHeadingIds.ts
@@ -11,7 +11,7 @@ import {
   writeMarkdownHeadingId,
   type WriteHeadingIDOptions,
 } from '@docusaurus/utils';
-import {loadContext} from '../server';
+import {loadContext} from '../server/site';
 import {initPlugins} from '../server/plugins/init';
 import {safeGlobby} from '../server/utils';
 
diff --git a/packages/docusaurus/src/commands/writeTranslations.ts b/packages/docusaurus/src/commands/writeTranslations.ts
index 6247f04902dc..9b94cedae28c 100644
--- a/packages/docusaurus/src/commands/writeTranslations.ts
+++ b/packages/docusaurus/src/commands/writeTranslations.ts
@@ -7,7 +7,7 @@
 
 import fs from 'fs-extra';
 import path from 'path';
-import {loadContext, type LoadContextOptions} from '../server';
+import {loadContext, type LoadContextParams} from '../server/site';
 import {initPlugins} from '../server/plugins/init';
 import {
   writePluginTranslations,
@@ -24,7 +24,7 @@ import {getCustomBabelConfigFilePath, getBabelOptions} from '../webpack/utils';
 import type {InitializedPlugin} from '@docusaurus/types';
 
 export type WriteTranslationsCLIOptions = Pick<
-  LoadContextOptions,
+  LoadContextParams,
   'config' | 'locale'
 > &
   WriteTranslationsOptions;
diff --git a/packages/docusaurus/src/index.ts b/packages/docusaurus/src/index.ts
index 097eaad0e077..82ba70af2e93 100644
--- a/packages/docusaurus/src/index.ts
+++ b/packages/docusaurus/src/index.ts
@@ -10,7 +10,7 @@ export {clear} from './commands/clear';
 export {deploy} from './commands/deploy';
 export {externalCommand} from './commands/external';
 export {serve} from './commands/serve';
-export {start} from './commands/start';
+export {start} from './commands/start/start';
 export {swizzle} from './commands/swizzle';
 export {writeHeadingIds} from './commands/writeHeadingIds';
 export {writeTranslations} from './commands/writeTranslations';
diff --git a/packages/docusaurus/src/server/__tests__/__snapshots__/index.test.ts.snap b/packages/docusaurus/src/server/__tests__/__snapshots__/site.test.ts.snap
similarity index 100%
rename from packages/docusaurus/src/server/__tests__/__snapshots__/index.test.ts.snap
rename to packages/docusaurus/src/server/__tests__/__snapshots__/site.test.ts.snap
diff --git a/packages/docusaurus/src/server/__tests__/routes.test.ts b/packages/docusaurus/src/server/__tests__/routes.test.ts
index f302b3c4506d..278fbf9583fe 100644
--- a/packages/docusaurus/src/server/__tests__/routes.test.ts
+++ b/packages/docusaurus/src/server/__tests__/routes.test.ts
@@ -6,89 +6,30 @@
  */
 
 import {jest} from '@jest/globals';
-import {loadRoutes, handleDuplicateRoutes, genChunkName} from '../routes';
+import {getAllFinalRoutes, handleDuplicateRoutes} from '../routes';
 import type {RouteConfig} from '@docusaurus/types';
 
-describe('genChunkName', () => {
-  it('works', () => {
-    const firstAssert: {[key: string]: string} = {
-      '/docs/adding-blog': 'docs-adding-blog-062',
-      '/docs/versioning': 'docs-versioning-8a8',
-      '/': 'index',
-      '/blog/2018/04/30/How-I-Converted-Profilo-To-Docusaurus':
-        'blog-2018-04-30-how-i-converted-profilo-to-docusaurus-4f2',
-      '/youtube': 'youtube-429',
-      '/users/en/': 'users-en-f7a',
-      '/blog': 'blog-c06',
-    };
-    Object.keys(firstAssert).forEach((str) => {
-      expect(genChunkName(str)).toBe(firstAssert[str]);
-    });
-  });
-
-  it("doesn't allow different chunk name for same path", () => {
-    expect(genChunkName('path/is/similar', 'oldPrefix')).toEqual(
-      genChunkName('path/is/similar', 'newPrefix'),
-    );
-  });
-
-  it('emits different chunk names for different paths even with same preferred name', () => {
-    const secondAssert: {[key: string]: string} = {
-      '/blog/1': 'blog-85-f-089',
-      '/blog/2': 'blog-353-489',
-    };
-    Object.keys(secondAssert).forEach((str) => {
-      expect(genChunkName(str, undefined, 'blog')).toBe(secondAssert[str]);
-    });
-  });
-
-  it('only generates short unique IDs', () => {
-    const thirdAssert: {[key: string]: string} = {
-      a: '0cc175b9',
-      b: '92eb5ffe',
-      c: '4a8a08f0',
-      d: '8277e091',
-    };
-    Object.keys(thirdAssert).forEach((str) => {
-      expect(genChunkName(str, undefined, undefined, true)).toBe(
-        thirdAssert[str],
-      );
-    });
-    expect(genChunkName('d', undefined, undefined, true)).toBe('8277e091');
-  });
-
-  // https://github.com/facebook/docusaurus/issues/8536
-  it('avoids hash collisions', () => {
-    expect(
-      genChunkName(
-        '@site/blog/2022-11-18-bye-medium/index.mdx?truncated=true',
-        'content',
-        'blog',
-        false,
-      ),
-    ).not.toBe(
-      genChunkName(
-        '@site/blog/2019-10-05-react-nfc/index.mdx?truncated=true',
-        'content',
-        'blog',
-        false,
-      ),
-    );
-    expect(
-      genChunkName(
-        '@site/blog/2022-11-18-bye-medium/index.mdx?truncated=true',
-        'content',
-        'blog',
-        true,
-      ),
-    ).not.toBe(
-      genChunkName(
-        '@site/blog/2019-10-05-react-nfc/index.mdx?truncated=true',
-        'content',
-        'blog',
-        true,
-      ),
-    );
+describe('getAllFinalRoutes', () => {
+  it('gets final routes correctly', () => {
+    const routes: RouteConfig[] = [
+      {
+        path: '/docs',
+        component: '',
+        routes: [
+          {path: '/docs/someDoc', component: ''},
+          {path: '/docs/someOtherDoc', component: ''},
+        ],
+      },
+      {
+        path: '/community',
+        component: '',
+      },
+    ];
+    expect(getAllFinalRoutes(routes)).toEqual([
+      routes[0]!.routes![0],
+      routes[0]!.routes![1],
+      routes[1],
+    ]);
   });
 });
 
@@ -127,117 +68,16 @@ describe('handleDuplicateRoutes', () => {
   it('works', () => {
     expect(() => {
       handleDuplicateRoutes(routes, 'throw');
-    }).toThrowErrorMatchingSnapshot();
+    }).toThrowErrorMatchingInlineSnapshot(`
+      "Duplicate routes found!
+      - Attempting to create page at /search, but a page already exists at this route.
+      - Attempting to create page at /sameDoc, but a page already exists at this route.
+      - Attempting to create page at /, but a page already exists at this route.
+      - Attempting to create page at /, but a page already exists at this route.
+      This could lead to non-deterministic routing behavior."
+    `);
     const consoleMock = jest.spyOn(console, 'log').mockImplementation(() => {});
     handleDuplicateRoutes(routes, 'ignore');
     expect(consoleMock).toHaveBeenCalledTimes(0);
   });
 });
-
-describe('loadRoutes', () => {
-  it('loads nested route config', () => {
-    const nestedRouteConfig: RouteConfig = {
-      component: '@theme/DocRoot',
-      path: '/docs:route',
-      modules: {
-        docsMetadata: 'docs-b5f.json',
-      },
-      routes: [
-        {
-          path: '/docs/hello',
-          component: '@theme/DocItem',
-          exact: true,
-          modules: {
-            content: 'docs/hello.md',
-            metadata: 'docs-hello-da2.json',
-          },
-          context: {
-            plugin: 'pluginRouteContextModule-100.json',
-          },
-          sidebar: 'main',
-        },
-        {
-          path: 'docs/foo/baz',
-          component: '@theme/DocItem',
-          modules: {
-            content: 'docs/foo/baz.md',
-            metadata: 'docs-foo-baz-dd9.json',
-          },
-          context: {
-            plugin: 'pluginRouteContextModule-100.json',
-          },
-          sidebar: 'secondary',
-          'key:a': 'containing colon',
-          "key'b": 'containing quote',
-          'key"c': 'containing double quote',
-          'key,d': 'containing comma',
-          字段: 'containing unicode',
-        },
-      ],
-    };
-    expect(loadRoutes([nestedRouteConfig], '/', 'ignore')).toMatchSnapshot();
-  });
-
-  it('loads flat route config', () => {
-    const flatRouteConfig: RouteConfig = {
-      path: '/blog',
-      component: '@theme/BlogListPage',
-      exact: true,
-      modules: {
-        items: [
-          {
-            content: {
-              __import: true,
-              path: 'blog/2018-12-14-Happy-First-Birthday-Slash.md',
-              query: {
-                truncated: true,
-              },
-            },
-            metadata: 'blog-2018-12-14-happy-first-birthday-slash-d2c.json',
-          },
-          {
-            content: 'blog/2018-12-14-Happy-First-Birthday-Slash.md',
-          },
-          {
-            content: {
-              __import: true,
-              path: 'blog/2018-12-14-Happy-First-Birthday-Slash.md',
-            },
-          },
-        ],
-      },
-    };
-    expect(loadRoutes([flatRouteConfig], '/', 'ignore')).toMatchSnapshot();
-  });
-
-  it('rejects invalid route config', () => {
-    const routeConfigWithoutPath = {
-      component: 'hello/world.js',
-    } as RouteConfig;
-
-    expect(() => loadRoutes([routeConfigWithoutPath], '/', 'ignore'))
-      .toThrowErrorMatchingInlineSnapshot(`
-      "Invalid route config: path must be a string and component is required.
-      {"component":"hello/world.js"}"
-    `);
-
-    const routeConfigWithoutComponent = {
-      path: '/hello/world',
-    } as RouteConfig;
-
-    expect(() => loadRoutes([routeConfigWithoutComponent], '/', 'ignore'))
-      .toThrowErrorMatchingInlineSnapshot(`
-      "Invalid route config: path must be a string and component is required.
-      {"path":"/hello/world"}"
-    `);
-  });
-
-  it('loads route config with empty (but valid) path string', () => {
-    const routeConfig = {
-      path: '',
-      component: 'hello/world.js',
-    } as RouteConfig;
-
-    expect(loadRoutes([routeConfig], '/', 'ignore')).toMatchSnapshot();
-  });
-});
diff --git a/packages/docusaurus/src/server/__tests__/index.test.ts b/packages/docusaurus/src/server/__tests__/site.test.ts
similarity index 81%
rename from packages/docusaurus/src/server/__tests__/index.test.ts
rename to packages/docusaurus/src/server/__tests__/site.test.ts
index 28bdc3f265e3..235060c3e445 100644
--- a/packages/docusaurus/src/server/__tests__/index.test.ts
+++ b/packages/docusaurus/src/server/__tests__/site.test.ts
@@ -13,15 +13,15 @@ import type {DeepPartial} from 'utility-types';
 
 describe('load', () => {
   it('loads props for site with custom i18n path', async () => {
-    const props = await loadSetup('custom-i18n-site');
-    expect(props).toMatchSnapshot();
-    const props2 = await loadSetup('custom-i18n-site', {locale: 'zh-Hans'});
-    expect(props2).toEqual(
+    const site = await loadSetup('custom-i18n-site');
+    expect(site.props).toMatchSnapshot();
+    const site2 = await loadSetup('custom-i18n-site', {locale: 'zh-Hans'});
+    expect(site2.props).toEqual(
       mergeWithCustomize<DeepPartial<Props>>({
         customizeArray(a, b, key) {
           return ['routesPaths', 'plugins'].includes(key) ? b : undefined;
         },
-      })(props, {
+      })(site.props, {
         baseUrl: '/zh-Hans/',
         i18n: {
           currentLocale: 'zh-Hans',
@@ -38,7 +38,7 @@ describe('load', () => {
         siteConfig: {
           baseUrl: '/zh-Hans/',
         },
-        plugins: props2.plugins,
+        plugins: site2.props.plugins,
       }),
     );
   });
diff --git a/packages/docusaurus/src/server/__tests__/testUtils.ts b/packages/docusaurus/src/server/__tests__/testUtils.ts
index c295f05dad51..178c3c1c2452 100644
--- a/packages/docusaurus/src/server/__tests__/testUtils.ts
+++ b/packages/docusaurus/src/server/__tests__/testUtils.ts
@@ -6,14 +6,14 @@
  */
 
 import path from 'path';
-import {load, type LoadContextOptions} from '../index';
-import type {Props} from '@docusaurus/types';
+import {loadSite, type LoadContextParams} from '../site';
+import type {Site} from '@docusaurus/types';
 
 // Helper methods to setup dummy/fake projects.
 export async function loadSetup(
   name: string,
-  options?: Partial<LoadContextOptions>,
-): Promise<Props> {
+  options?: Partial<LoadContextParams>,
+): Promise<Site> {
   const fixtures = path.join(__dirname, '__fixtures__');
-  return load({siteDir: path.join(fixtures, name), ...options});
+  return loadSite({siteDir: path.join(fixtures, name), ...options});
 }
diff --git a/packages/docusaurus/src/server/__tests__/utils.test.ts b/packages/docusaurus/src/server/__tests__/utils.test.ts
deleted file mode 100644
index a93adea41f69..000000000000
--- a/packages/docusaurus/src/server/__tests__/utils.test.ts
+++ /dev/null
@@ -1,33 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {getAllFinalRoutes} from '../utils';
-import type {RouteConfig} from '@docusaurus/types';
-
-describe('getAllFinalRoutes', () => {
-  it('gets final routes correctly', () => {
-    const routes: RouteConfig[] = [
-      {
-        path: '/docs',
-        component: '',
-        routes: [
-          {path: '/docs/someDoc', component: ''},
-          {path: '/docs/someOtherDoc', component: ''},
-        ],
-      },
-      {
-        path: '/community',
-        component: '',
-      },
-    ];
-    expect(getAllFinalRoutes(routes)).toEqual([
-      routes[0]!.routes![0],
-      routes[0]!.routes![1],
-      routes[1],
-    ]);
-  });
-});
diff --git a/packages/docusaurus/src/server/brokenLinks.ts b/packages/docusaurus/src/server/brokenLinks.ts
index c91c2f1faecc..acdc016a1ff4 100644
--- a/packages/docusaurus/src/server/brokenLinks.ts
+++ b/packages/docusaurus/src/server/brokenLinks.ts
@@ -15,7 +15,7 @@ import {
   serializeURLPath,
   type URLPath,
 } from '@docusaurus/utils';
-import {getAllFinalRoutes} from './utils';
+import {getAllFinalRoutes} from './routes';
 import type {RouteConfig, ReportingSeverity} from '@docusaurus/types';
 
 function matchRoutes(routeConfig: RouteConfig[], pathname: string) {
diff --git a/packages/docusaurus/src/server/__tests__/__snapshots__/routes.test.ts.snap b/packages/docusaurus/src/server/codegen/__tests__/__snapshots__/codegenRoutes.test.ts.snap
similarity index 85%
rename from packages/docusaurus/src/server/__tests__/__snapshots__/routes.test.ts.snap
rename to packages/docusaurus/src/server/codegen/__tests__/__snapshots__/codegenRoutes.test.ts.snap
index 9fe2fabb5ff4..2a6e4784b523 100644
--- a/packages/docusaurus/src/server/__tests__/__snapshots__/routes.test.ts.snap
+++ b/packages/docusaurus/src/server/codegen/__tests__/__snapshots__/codegenRoutes.test.ts.snap
@@ -1,14 +1,5 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`handleDuplicateRoutes works 1`] = `
-"Duplicate routes found!
-- Attempting to create page at /search, but a page already exists at this route.
-- Attempting to create page at /sameDoc, but a page already exists at this route.
-- Attempting to create page at /, but a page already exists at this route.
-- Attempting to create page at /, but a page already exists at this route.
-This could lead to non-deterministic routing behavior."
-`;
-
 exports[`loadRoutes loads flat route config 1`] = `
 {
   "registry": {
@@ -49,10 +40,6 @@ export default [
   },
 ];
 ",
-  "routesPaths": [
-    "/404.html",
-    "/blog",
-  ],
 }
 `;
 
@@ -122,11 +109,6 @@ export default [
   },
 ];
 ",
-  "routesPaths": [
-    "/404.html",
-    "/docs/hello",
-    "docs/foo/baz",
-  ],
 }
 `;
 
@@ -154,9 +136,5 @@ export default [
   },
 ];
 ",
-  "routesPaths": [
-    "/404.html",
-    "",
-  ],
 }
 `;
diff --git a/packages/docusaurus/src/server/codegen/__tests__/codegenRoutes.test.ts b/packages/docusaurus/src/server/codegen/__tests__/codegenRoutes.test.ts
new file mode 100644
index 000000000000..bfcfe123470b
--- /dev/null
+++ b/packages/docusaurus/src/server/codegen/__tests__/codegenRoutes.test.ts
@@ -0,0 +1,205 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {generateRoutesCode, genChunkName} from '../codegenRoutes';
+import type {RouteConfig} from '@docusaurus/types';
+
+describe('genChunkName', () => {
+  it('works', () => {
+    const firstAssert: {[key: string]: string} = {
+      '/docs/adding-blog': 'docs-adding-blog-062',
+      '/docs/versioning': 'docs-versioning-8a8',
+      '/': 'index',
+      '/blog/2018/04/30/How-I-Converted-Profilo-To-Docusaurus':
+        'blog-2018-04-30-how-i-converted-profilo-to-docusaurus-4f2',
+      '/youtube': 'youtube-429',
+      '/users/en/': 'users-en-f7a',
+      '/blog': 'blog-c06',
+    };
+    Object.keys(firstAssert).forEach((str) => {
+      expect(genChunkName(str)).toBe(firstAssert[str]);
+    });
+  });
+
+  it("doesn't allow different chunk name for same path", () => {
+    expect(genChunkName('path/is/similar', 'oldPrefix')).toEqual(
+      genChunkName('path/is/similar', 'newPrefix'),
+    );
+  });
+
+  it('emits different chunk names for different paths even with same preferred name', () => {
+    const secondAssert: {[key: string]: string} = {
+      '/blog/1': 'blog-85-f-089',
+      '/blog/2': 'blog-353-489',
+    };
+    Object.keys(secondAssert).forEach((str) => {
+      expect(genChunkName(str, undefined, 'blog')).toBe(secondAssert[str]);
+    });
+  });
+
+  it('only generates short unique IDs', () => {
+    const thirdAssert: {[key: string]: string} = {
+      a: '0cc175b9',
+      b: '92eb5ffe',
+      c: '4a8a08f0',
+      d: '8277e091',
+    };
+    Object.keys(thirdAssert).forEach((str) => {
+      expect(genChunkName(str, undefined, undefined, true)).toBe(
+        thirdAssert[str],
+      );
+    });
+    expect(genChunkName('d', undefined, undefined, true)).toBe('8277e091');
+  });
+
+  // https://github.com/facebook/docusaurus/issues/8536
+  it('avoids hash collisions', () => {
+    expect(
+      genChunkName(
+        '@site/blog/2022-11-18-bye-medium/index.mdx?truncated=true',
+        'content',
+        'blog',
+        false,
+      ),
+    ).not.toBe(
+      genChunkName(
+        '@site/blog/2019-10-05-react-nfc/index.mdx?truncated=true',
+        'content',
+        'blog',
+        false,
+      ),
+    );
+    expect(
+      genChunkName(
+        '@site/blog/2022-11-18-bye-medium/index.mdx?truncated=true',
+        'content',
+        'blog',
+        true,
+      ),
+    ).not.toBe(
+      genChunkName(
+        '@site/blog/2019-10-05-react-nfc/index.mdx?truncated=true',
+        'content',
+        'blog',
+        true,
+      ),
+    );
+  });
+});
+
+describe('loadRoutes', () => {
+  it('loads nested route config', () => {
+    const nestedRouteConfig: RouteConfig = {
+      component: '@theme/DocRoot',
+      path: '/docs:route',
+      modules: {
+        docsMetadata: 'docs-b5f.json',
+      },
+      routes: [
+        {
+          path: '/docs/hello',
+          component: '@theme/DocItem',
+          exact: true,
+          modules: {
+            content: 'docs/hello.md',
+            metadata: 'docs-hello-da2.json',
+          },
+          context: {
+            plugin: 'pluginRouteContextModule-100.json',
+          },
+          sidebar: 'main',
+        },
+        {
+          path: 'docs/foo/baz',
+          component: '@theme/DocItem',
+          modules: {
+            content: 'docs/foo/baz.md',
+            metadata: 'docs-foo-baz-dd9.json',
+          },
+          context: {
+            plugin: 'pluginRouteContextModule-100.json',
+          },
+          sidebar: 'secondary',
+          'key:a': 'containing colon',
+          "key'b": 'containing quote',
+          'key"c': 'containing double quote',
+          'key,d': 'containing comma',
+          字段: 'containing unicode',
+        },
+      ],
+    };
+    expect(
+      generateRoutesCode([nestedRouteConfig], '/', 'ignore'),
+    ).toMatchSnapshot();
+  });
+
+  it('loads flat route config', () => {
+    const flatRouteConfig: RouteConfig = {
+      path: '/blog',
+      component: '@theme/BlogListPage',
+      exact: true,
+      modules: {
+        items: [
+          {
+            content: {
+              __import: true,
+              path: 'blog/2018-12-14-Happy-First-Birthday-Slash.md',
+              query: {
+                truncated: true,
+              },
+            },
+            metadata: 'blog-2018-12-14-happy-first-birthday-slash-d2c.json',
+          },
+          {
+            content: 'blog/2018-12-14-Happy-First-Birthday-Slash.md',
+          },
+          {
+            content: {
+              __import: true,
+              path: 'blog/2018-12-14-Happy-First-Birthday-Slash.md',
+            },
+          },
+        ],
+      },
+    };
+    expect(
+      generateRoutesCode([flatRouteConfig], '/', 'ignore'),
+    ).toMatchSnapshot();
+  });
+
+  it('rejects invalid route config', () => {
+    const routeConfigWithoutPath = {
+      component: 'hello/world.js',
+    } as RouteConfig;
+
+    expect(() => generateRoutesCode([routeConfigWithoutPath], '/', 'ignore'))
+      .toThrowErrorMatchingInlineSnapshot(`
+      "Invalid route config: path must be a string and component is required.
+      {"component":"hello/world.js"}"
+    `);
+
+    const routeConfigWithoutComponent = {
+      path: '/hello/world',
+    } as RouteConfig;
+
+    expect(() =>
+      generateRoutesCode([routeConfigWithoutComponent], '/', 'ignore'),
+    ).toThrowErrorMatchingInlineSnapshot(`
+      "Invalid route config: path must be a string and component is required.
+      {"path":"/hello/world"}"
+    `);
+  });
+
+  it('loads route config with empty (but valid) path string', () => {
+    const routeConfig = {
+      path: '',
+      component: 'hello/world.js',
+    } as RouteConfig;
+
+    expect(generateRoutesCode([routeConfig], '/', 'ignore')).toMatchSnapshot();
+  });
+});
diff --git a/packages/docusaurus/src/server/codegen/codegen.ts b/packages/docusaurus/src/server/codegen/codegen.ts
new file mode 100644
index 000000000000..69450426826f
--- /dev/null
+++ b/packages/docusaurus/src/server/codegen/codegen.ts
@@ -0,0 +1,157 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {
+  generate,
+  escapePath,
+  DEFAULT_CONFIG_FILE_NAME,
+} from '@docusaurus/utils';
+import {generateRouteFiles} from './codegenRoutes';
+import type {
+  CodeTranslations,
+  DocusaurusConfig,
+  GlobalData,
+  I18n,
+  RouteConfig,
+  SiteMetadata,
+} from '@docusaurus/types';
+
+function genWarning({generatedFilesDir}: {generatedFilesDir: string}) {
+  return generate(
+    generatedFilesDir,
+    // cSpell:ignore DONT
+    'DONT-EDIT-THIS-FOLDER',
+    `This folder stores temp files that Docusaurus' client bundler accesses.
+
+DO NOT hand-modify files in this folder because they will be overwritten in the
+next build. You can clear all build artifacts (including this folder) with the
+\`docusaurus clear\` command.
+`,
+  );
+}
+
+function genSiteConfig({
+  generatedFilesDir,
+  siteConfig,
+}: {
+  generatedFilesDir: string;
+  siteConfig: DocusaurusConfig;
+}) {
+  return generate(
+    generatedFilesDir,
+    `${DEFAULT_CONFIG_FILE_NAME}.mjs`,
+    `/*
+ * AUTOGENERATED - DON'T EDIT
+ * Your edits in this file will be overwritten in the next build!
+ * Modify the docusaurus.config.js file at your site's root instead.
+ */
+export default ${JSON.stringify(siteConfig, null, 2)};
+`,
+  );
+}
+
+function genClientModules({
+  generatedFilesDir,
+  clientModules,
+}: {
+  generatedFilesDir: string;
+  clientModules: string[];
+}) {
+  return generate(
+    generatedFilesDir,
+    'client-modules.js',
+    `export default [
+${clientModules
+  // Use `require()` because `import()` is async but client modules can have CSS
+  // and the order matters for loading CSS.
+  .map((clientModule) => `  require("${escapePath(clientModule)}"),`)
+  .join('\n')}
+];
+`,
+  );
+}
+
+function genGlobalData({
+  generatedFilesDir,
+  globalData,
+}: {
+  generatedFilesDir: string;
+  globalData: GlobalData;
+}) {
+  return generate(
+    generatedFilesDir,
+    'globalData.json',
+    JSON.stringify(globalData, null, 2),
+  );
+}
+
+function genI18n({
+  generatedFilesDir,
+  i18n,
+}: {
+  generatedFilesDir: string;
+  i18n: I18n;
+}) {
+  return generate(
+    generatedFilesDir,
+    'i18n.json',
+    JSON.stringify(i18n, null, 2),
+  );
+}
+
+function genCodeTranslations({
+  generatedFilesDir,
+  codeTranslations,
+}: {
+  generatedFilesDir: string;
+  codeTranslations: CodeTranslations;
+}) {
+  return generate(
+    generatedFilesDir,
+    'codeTranslations.json',
+    JSON.stringify(codeTranslations, null, 2),
+  );
+}
+
+function genSiteMetadata({
+  generatedFilesDir,
+  siteMetadata,
+}: {
+  generatedFilesDir: string;
+  siteMetadata: SiteMetadata;
+}) {
+  return generate(
+    generatedFilesDir,
+    'site-metadata.json',
+    JSON.stringify(siteMetadata, null, 2),
+  );
+}
+
+type CodegenParams = {
+  generatedFilesDir: string;
+  siteConfig: DocusaurusConfig;
+  baseUrl: string;
+  clientModules: string[];
+  globalData: GlobalData;
+  i18n: I18n;
+  codeTranslations: CodeTranslations;
+  siteMetadata: SiteMetadata;
+  routes: RouteConfig[];
+};
+
+export async function generateSiteFiles(params: CodegenParams): Promise<void> {
+  await Promise.all([
+    genWarning(params),
+    genClientModules(params),
+    genSiteConfig(params),
+    generateRouteFiles(params),
+    genGlobalData(params),
+    genSiteMetadata(params),
+    genI18n(params),
+    genCodeTranslations(params),
+  ]);
+}
diff --git a/packages/docusaurus/src/server/codegen/codegenRoutes.ts b/packages/docusaurus/src/server/codegen/codegenRoutes.ts
new file mode 100644
index 000000000000..8306e0f78d99
--- /dev/null
+++ b/packages/docusaurus/src/server/codegen/codegenRoutes.ts
@@ -0,0 +1,327 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import query from 'querystring';
+import _ from 'lodash';
+import {docuHash, simpleHash, escapePath, generate} from '@docusaurus/utils';
+import type {
+  Module,
+  RouteConfig,
+  RouteModules,
+  ChunkNames,
+  RouteChunkNames,
+} from '@docusaurus/types';
+
+type RoutesCode = {
+  /** Serialized routes config that can be directly emitted into temp file. */
+  routesConfig: string;
+  /** @see {ChunkNames} */
+  routesChunkNames: RouteChunkNames;
+  /**
+   * A map from chunk name to module paths. Module paths would have backslash
+   * escaped already, so they can be directly printed.
+   */
+  registry: {
+    [chunkName: string]: string;
+  };
+};
+
+/** Indents every line of `str` by one level. */
+function indent(str: string) {
+  return `  ${str.replace(/\n/g, `\n  `)}`;
+}
+
+const chunkNameCache = new Map<string, string>();
+const chunkNameCount = new Map<string, number>();
+
+/**
+ * Generates a unique chunk name that can be used in the chunk registry.
+ *
+ * @param modulePath A path to generate chunk name from. The actual value has no
+ * semantic significance.
+ * @param prefix A prefix to append to the chunk name, to avoid name clash.
+ * @param preferredName Chunk names default to `modulePath`, and this can supply
+ * a more human-readable name.
+ * @param shortId When `true`, the chunk name would only be a hash without any
+ * other characters. Useful for bundle size. Defaults to `true` in production.
+ */
+export function genChunkName(
+  modulePath: string,
+  prefix?: string,
+  preferredName?: string,
+  shortId: boolean = process.env.NODE_ENV === 'production',
+): string {
+  let chunkName = chunkNameCache.get(modulePath);
+  if (!chunkName) {
+    if (shortId) {
+      chunkName = simpleHash(modulePath, 8);
+    } else {
+      let str = modulePath;
+      if (preferredName) {
+        const shortHash = simpleHash(modulePath, 3);
+        str = `${preferredName}${shortHash}`;
+      }
+      const name = docuHash(str);
+      chunkName = prefix ? `${prefix}---${name}` : name;
+    }
+    const seenCount = (chunkNameCount.get(chunkName) ?? 0) + 1;
+    if (seenCount > 1) {
+      chunkName += seenCount.toString(36);
+    }
+    chunkNameCache.set(modulePath, chunkName);
+    chunkNameCount.set(chunkName, seenCount);
+  }
+  return chunkName;
+}
+
+/**
+ * Takes a piece of route config, and serializes it into raw JS code. The shape
+ * is the same as react-router's `RouteConfig`. Formatting is similar to
+ * `JSON.stringify` but without all the quotes.
+ */
+function serializeRouteConfig({
+  routePath,
+  routeHash,
+  exact,
+  subroutesCodeStrings,
+  props,
+}: {
+  routePath: string;
+  routeHash: string;
+  exact?: boolean;
+  subroutesCodeStrings?: string[];
+  props: {[propName: string]: unknown};
+}) {
+  const parts = [
+    `path: '${routePath}'`,
+    `component: ComponentCreator('${routePath}', '${routeHash}')`,
+  ];
+
+  if (exact) {
+    parts.push(`exact: true`);
+  }
+
+  if (subroutesCodeStrings) {
+    parts.push(
+      `routes: [
+${indent(subroutesCodeStrings.join(',\n'))}
+]`,
+    );
+  }
+
+  Object.entries(props).forEach(([propName, propValue]) => {
+    const isIdentifier =
+      /^[$_\p{ID_Start}][$\u200c\u200d\p{ID_Continue}]*$/u.test(propName);
+    const key = isIdentifier ? propName : JSON.stringify(propName);
+    parts.push(`${key}: ${JSON.stringify(propValue)}`);
+  });
+
+  return `{
+${indent(parts.join(',\n'))}
+}`;
+}
+
+const isModule = (value: unknown): value is Module =>
+  typeof value === 'string' ||
+  (typeof value === 'object' &&
+    // eslint-disable-next-line no-underscore-dangle
+    !!(value as {[key: string]: unknown} | null)?.__import);
+
+/**
+ * Takes a {@link Module} (which is nothing more than a path plus some metadata
+ * like query) and returns the string path it represents.
+ */
+function getModulePath(target: Module): string {
+  if (typeof target === 'string') {
+    return target;
+  }
+  const queryStr = target.query ? `?${query.stringify(target.query)}` : '';
+  return `${target.path}${queryStr}`;
+}
+
+/**
+ * Takes a route module (which is a tree of modules), and transforms each module
+ * into a chunk name. It also mutates `res.registry` and registers the loaders
+ * for each chunk.
+ *
+ * @param routeModule One route module to be transformed.
+ * @param prefix Prefix passed to {@link genChunkName}.
+ * @param name Preferred name passed to {@link genChunkName}.
+ * @param res The route structures being loaded.
+ */
+function genChunkNames(
+  routeModule: RouteModules,
+  prefix: string,
+  name: string,
+  res: RoutesCode,
+): ChunkNames;
+function genChunkNames(
+  routeModule: RouteModules | RouteModules[] | Module,
+  prefix: string,
+  name: string,
+  res: RoutesCode,
+): ChunkNames | ChunkNames[] | string;
+function genChunkNames(
+  routeModule: RouteModules | RouteModules[] | Module,
+  prefix: string,
+  name: string,
+  res: RoutesCode,
+): string | ChunkNames | ChunkNames[] {
+  if (isModule(routeModule)) {
+    // This is a leaf node, no need to recurse
+    const modulePath = getModulePath(routeModule);
+    const chunkName = genChunkName(modulePath, prefix, name);
+    res.registry[chunkName] = escapePath(modulePath);
+    return chunkName;
+  }
+  if (Array.isArray(routeModule)) {
+    return routeModule.map((val, index) =>
+      genChunkNames(val, `${index}`, name, res),
+    );
+  }
+  return _.mapValues(routeModule, (v, key) => genChunkNames(v, key, name, res));
+}
+
+/**
+ * This is the higher level overview of route code generation. For each route
+ * config node, it returns the node's serialized form, and mutates `registry`,
+ * `routesPaths`, and `routesChunkNames` accordingly.
+ */
+function genRouteCode(routeConfig: RouteConfig, res: RoutesCode): string {
+  const {
+    path: routePath,
+    component,
+    modules = {},
+    context,
+    routes: subroutes,
+    priority,
+    exact,
+    ...props
+  } = routeConfig;
+
+  if (typeof routePath !== 'string' || !component) {
+    throw new Error(
+      `Invalid route config: path must be a string and component is required.
+${JSON.stringify(routeConfig)}`,
+    );
+  }
+
+  const routeHash = simpleHash(JSON.stringify(routeConfig), 3);
+  res.routesChunkNames[`${routePath}-${routeHash}`] = {
+    // Avoid clash with a prop called "component"
+    ...genChunkNames({__comp: component}, 'component', component, res),
+    ...(context &&
+      genChunkNames({__context: context}, 'context', routePath, res)),
+    ...genChunkNames(modules, 'module', routePath, res),
+  };
+
+  return serializeRouteConfig({
+    routePath: routePath.replace(/'/g, "\\'"),
+    routeHash,
+    subroutesCodeStrings: subroutes?.map((r) => genRouteCode(r, res)),
+    exact,
+    props,
+  });
+}
+
+/**
+ * Routes are prepared into three temp files:
+ *
+ * - `routesConfig`, the route config passed to react-router. This file is kept
+ * minimal, because it can't be code-splitted.
+ * - `routesChunkNames`, a mapping from route paths (hashed) to code-splitted
+ * chunk names.
+ * - `registry`, a mapping from chunk names to options for react-loadable.
+ */
+export function generateRoutesCode(routeConfigs: RouteConfig[]): RoutesCode {
+  const res: RoutesCode = {
+    // To be written by `genRouteCode`
+    routesConfig: '',
+    routesChunkNames: {},
+    registry: {},
+  };
+
+  // `genRouteCode` would mutate `res`
+  const routeConfigSerialized = routeConfigs
+    .map((r) => genRouteCode(r, res))
+    .join(',\n');
+
+  res.routesConfig = `import React from 'react';
+import ComponentCreator from '@docusaurus/ComponentCreator';
+
+export default [
+${indent(routeConfigSerialized)},
+  {
+    path: '*',
+    component: ComponentCreator('*'),
+  },
+];
+`;
+
+  return res;
+}
+
+const genRegistry = ({
+  generatedFilesDir,
+  registry,
+}: {
+  generatedFilesDir: string;
+  registry: RoutesCode['registry'];
+}) =>
+  generate(
+    generatedFilesDir,
+    'registry.js',
+    `export default {
+${Object.entries(registry)
+  .sort((a, b) => a[0].localeCompare(b[0]))
+  .map(
+    ([chunkName, modulePath]) =>
+      // modulePath is already escaped by escapePath
+      `  "${chunkName}": [() => import(/* webpackChunkName: "${chunkName}" */ "${modulePath}"), "${modulePath}", require.resolveWeak("${modulePath}")],`,
+  )
+  .join('\n')}};
+`,
+  );
+
+const genRoutesChunkNames = ({
+  generatedFilesDir,
+  routesChunkNames,
+}: {
+  generatedFilesDir: string;
+  routesChunkNames: RoutesCode['routesChunkNames'];
+}) =>
+  generate(
+    generatedFilesDir,
+    'routesChunkNames.json',
+    JSON.stringify(routesChunkNames, null, 2),
+  );
+
+const genRoutes = ({
+  generatedFilesDir,
+  routesConfig,
+}: {
+  generatedFilesDir: string;
+  routesConfig: RoutesCode['routesConfig'];
+}) => generate(generatedFilesDir, 'routes.js', routesConfig);
+
+type GenerateRouteFilesParams = {
+  generatedFilesDir: string;
+  routes: RouteConfig[];
+  baseUrl: string;
+};
+
+export async function generateRouteFiles({
+  generatedFilesDir,
+  routes,
+}: GenerateRouteFilesParams): Promise<void> {
+  const {registry, routesChunkNames, routesConfig} = generateRoutesCode(routes);
+  await Promise.all([
+    genRegistry({generatedFilesDir, registry}),
+    genRoutesChunkNames({generatedFilesDir, routesChunkNames}),
+    genRoutes({generatedFilesDir, routesConfig}),
+  ]);
+}
diff --git a/packages/docusaurus/src/server/i18n.ts b/packages/docusaurus/src/server/i18n.ts
index 21f1b5ebd3b6..f87cc0e93cb8 100644
--- a/packages/docusaurus/src/server/i18n.ts
+++ b/packages/docusaurus/src/server/i18n.ts
@@ -8,7 +8,7 @@
 import logger from '@docusaurus/logger';
 import {getLangDir} from 'rtl-detect';
 import type {I18n, DocusaurusConfig, I18nLocaleConfig} from '@docusaurus/types';
-import type {LoadContextOptions} from './index';
+import type {LoadContextParams} from './site';
 
 function getDefaultLocaleLabel(locale: string) {
   const languageName = new Intl.DisplayNames(locale, {type: 'language'}).of(
@@ -55,7 +55,7 @@ export function getDefaultLocaleConfig(locale: string): I18nLocaleConfig {
 
 export async function loadI18n(
   config: DocusaurusConfig,
-  options: Pick<LoadContextOptions, 'locale'>,
+  options: Pick<LoadContextParams, 'locale'>,
 ): Promise<I18n> {
   const {i18n: i18nConfig} = config;
 
diff --git a/packages/docusaurus/src/server/index.ts b/packages/docusaurus/src/server/index.ts
deleted file mode 100644
index ab50c1883d31..000000000000
--- a/packages/docusaurus/src/server/index.ts
+++ /dev/null
@@ -1,266 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import path from 'path';
-import _ from 'lodash';
-import {
-  generate,
-  escapePath,
-  localizePath,
-  DEFAULT_BUILD_DIR_NAME,
-  DEFAULT_CONFIG_FILE_NAME,
-  GENERATED_FILES_DIR_NAME,
-} from '@docusaurus/utils';
-import {loadSiteConfig} from './config';
-import {loadClientModules} from './clientModules';
-import {loadPlugins} from './plugins';
-import {loadRoutes} from './routes';
-import {loadHtmlTags} from './htmlTags';
-import {loadSiteMetadata} from './siteMetadata';
-import {loadI18n} from './i18n';
-import {
-  readCodeTranslationFileContent,
-  getPluginsDefaultCodeTranslationMessages,
-} from './translations/translations';
-import type {DocusaurusConfig, LoadContext, Props} from '@docusaurus/types';
-
-export type LoadContextOptions = {
-  /** Usually the CWD; can be overridden with command argument. */
-  siteDir: string;
-  /** Custom output directory. Can be customized with `--out-dir` option */
-  outDir?: string;
-  /** Custom config path. Can be customized with `--config` option */
-  config?: string;
-  /** Default is `i18n.defaultLocale` */
-  locale?: string;
-  /**
-   * `true` means the paths will have the locale prepended; `false` means they
-   * won't (useful for `yarn build -l zh-Hans` where the output should be
-   * emitted into `build/` instead of `build/zh-Hans/`); `undefined` is like the
-   * "smart" option where only non-default locale paths are localized
-   */
-  localizePath?: boolean;
-};
-
-/**
- * Loading context is the very first step in site building. Its options are
- * directly acquired from CLI options. It mainly loads `siteConfig` and the i18n
- * context (which includes code translations). The `LoadContext` will be passed
- * to plugin constructors.
- */
-export async function loadContext(
-  options: LoadContextOptions,
-): Promise<LoadContext> {
-  const {
-    siteDir,
-    outDir: baseOutDir = DEFAULT_BUILD_DIR_NAME,
-    locale,
-    config: customConfigFilePath,
-  } = options;
-  const generatedFilesDir = path.resolve(siteDir, GENERATED_FILES_DIR_NAME);
-
-  const {siteConfig: initialSiteConfig, siteConfigPath} = await loadSiteConfig({
-    siteDir,
-    customConfigFilePath,
-  });
-
-  const i18n = await loadI18n(initialSiteConfig, {locale});
-
-  const baseUrl = localizePath({
-    path: initialSiteConfig.baseUrl,
-    i18n,
-    options,
-    pathType: 'url',
-  });
-  const outDir = localizePath({
-    path: path.resolve(siteDir, baseOutDir),
-    i18n,
-    options,
-    pathType: 'fs',
-  });
-
-  const siteConfig: DocusaurusConfig = {...initialSiteConfig, baseUrl};
-
-  const localizationDir = path.resolve(
-    siteDir,
-    i18n.path,
-    i18n.localeConfigs[i18n.currentLocale]!.path,
-  );
-
-  const codeTranslationFileContent =
-    (await readCodeTranslationFileContent({localizationDir})) ?? {};
-
-  // We only need key->message for code translations
-  const codeTranslations = _.mapValues(
-    codeTranslationFileContent,
-    (value) => value.message,
-  );
-
-  return {
-    siteDir,
-    generatedFilesDir,
-    localizationDir,
-    siteConfig,
-    siteConfigPath,
-    outDir,
-    baseUrl,
-    i18n,
-    codeTranslations,
-  };
-}
-
-/**
- * This is the crux of the Docusaurus server-side. It reads everything it needs—
- * code translations, config file, plugin modules... Plugins then use their
- * lifecycles to generate content and other data. It is side-effect-ful because
- * it generates temp files in the `.docusaurus` folder for the bundler.
- */
-export async function load(options: LoadContextOptions): Promise<Props> {
-  const {siteDir} = options;
-  const context = await loadContext(options);
-  const {
-    generatedFilesDir,
-    siteConfig,
-    siteConfigPath,
-    outDir,
-    baseUrl,
-    i18n,
-    localizationDir,
-    codeTranslations: siteCodeTranslations,
-  } = context;
-  const {plugins, pluginsRouteConfigs, globalData} = await loadPlugins(context);
-  const clientModules = loadClientModules(plugins);
-  const {headTags, preBodyTags, postBodyTags} = loadHtmlTags(plugins);
-  const {registry, routesChunkNames, routesConfig, routesPaths} = loadRoutes(
-    pluginsRouteConfigs,
-    baseUrl,
-    siteConfig.onDuplicateRoutes,
-  );
-  const codeTranslations = {
-    ...(await getPluginsDefaultCodeTranslationMessages(plugins)),
-    ...siteCodeTranslations,
-  };
-  const siteMetadata = await loadSiteMetadata({plugins, siteDir});
-
-  // === Side-effects part ===
-
-  const genWarning = generate(
-    generatedFilesDir,
-    // cSpell:ignore DONT
-    'DONT-EDIT-THIS-FOLDER',
-    `This folder stores temp files that Docusaurus' client bundler accesses.
-
-DO NOT hand-modify files in this folder because they will be overwritten in the
-next build. You can clear all build artifacts (including this folder) with the
-\`docusaurus clear\` command.
-`,
-  );
-
-  const genSiteConfig = generate(
-    generatedFilesDir,
-    `${DEFAULT_CONFIG_FILE_NAME}.mjs`,
-    `/*
- * AUTOGENERATED - DON'T EDIT
- * Your edits in this file will be overwritten in the next build!
- * Modify the docusaurus.config.js file at your site's root instead.
- */
-export default ${JSON.stringify(siteConfig, null, 2)};
-`,
-  );
-
-  const genClientModules = generate(
-    generatedFilesDir,
-    'client-modules.js',
-    `export default [
-${clientModules
-  // Use `require()` because `import()` is async but client modules can have CSS
-  // and the order matters for loading CSS.
-  .map((clientModule) => `  require("${escapePath(clientModule)}"),`)
-  .join('\n')}
-];
-`,
-  );
-
-  const genRegistry = generate(
-    generatedFilesDir,
-    'registry.js',
-    `export default {
-${Object.entries(registry)
-  .sort((a, b) => a[0].localeCompare(b[0]))
-  .map(
-    ([chunkName, modulePath]) =>
-      // modulePath is already escaped by escapePath
-      `  "${chunkName}": [() => import(/* webpackChunkName: "${chunkName}" */ "${modulePath}"), "${modulePath}", require.resolveWeak("${modulePath}")],`,
-  )
-  .join('\n')}};
-`,
-  );
-
-  const genRoutesChunkNames = generate(
-    generatedFilesDir,
-    'routesChunkNames.json',
-    JSON.stringify(routesChunkNames, null, 2),
-  );
-
-  const genRoutes = generate(generatedFilesDir, 'routes.js', routesConfig);
-
-  const genGlobalData = generate(
-    generatedFilesDir,
-    'globalData.json',
-    JSON.stringify(globalData, null, 2),
-  );
-
-  const genI18n = generate(
-    generatedFilesDir,
-    'i18n.json',
-    JSON.stringify(i18n, null, 2),
-  );
-
-  const genCodeTranslations = generate(
-    generatedFilesDir,
-    'codeTranslations.json',
-    JSON.stringify(codeTranslations, null, 2),
-  );
-
-  const genSiteMetadata = generate(
-    generatedFilesDir,
-    'site-metadata.json',
-    JSON.stringify(siteMetadata, null, 2),
-  );
-
-  await Promise.all([
-    genWarning,
-    genClientModules,
-    genSiteConfig,
-    genRegistry,
-    genRoutesChunkNames,
-    genRoutes,
-    genGlobalData,
-    genSiteMetadata,
-    genI18n,
-    genCodeTranslations,
-  ]);
-
-  return {
-    siteConfig,
-    siteConfigPath,
-    siteMetadata,
-    siteDir,
-    outDir,
-    baseUrl,
-    i18n,
-    localizationDir,
-    generatedFilesDir,
-    routes: pluginsRouteConfigs,
-    routesPaths,
-    plugins,
-    headTags,
-    preBodyTags,
-    postBodyTags,
-    codeTranslations,
-  };
-}
diff --git a/packages/docusaurus/src/server/plugins/__tests__/__snapshots__/index.test.ts.snap b/packages/docusaurus/src/server/plugins/__tests__/__snapshots__/plugins.test.ts.snap
similarity index 98%
rename from packages/docusaurus/src/server/plugins/__tests__/__snapshots__/index.test.ts.snap
rename to packages/docusaurus/src/server/plugins/__tests__/__snapshots__/plugins.test.ts.snap
index 76e6a9bee903..47295e904880 100644
--- a/packages/docusaurus/src/server/plugins/__tests__/__snapshots__/index.test.ts.snap
+++ b/packages/docusaurus/src/server/plugins/__tests__/__snapshots__/plugins.test.ts.snap
@@ -63,7 +63,7 @@ exports[`loadPlugins loads plugins 1`] = `
       },
     },
   ],
-  "pluginsRouteConfigs": [
+  "routes": [
     {
       "component": "Comp",
       "context": {
diff --git a/packages/docusaurus/src/server/plugins/__tests__/__snapshots__/routeConfig.test.ts.snap b/packages/docusaurus/src/server/plugins/__tests__/__snapshots__/routeConfig.test.ts.snap
index 9d4fb06e800a..69eb51472e60 100644
--- a/packages/docusaurus/src/server/plugins/__tests__/__snapshots__/routeConfig.test.ts.snap
+++ b/packages/docusaurus/src/server/plugins/__tests__/__snapshots__/routeConfig.test.ts.snap
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`sortConfig sorts route config correctly 1`] = `
+exports[`sortRoutes sorts route config correctly 1`] = `
 [
   {
     "component": "",
@@ -55,7 +55,7 @@ exports[`sortConfig sorts route config correctly 1`] = `
 ]
 `;
 
-exports[`sortConfig sorts route config given a baseURL 1`] = `
+exports[`sortRoutes sorts route config given a baseURL 1`] = `
 [
   {
     "component": "",
@@ -104,7 +104,153 @@ exports[`sortConfig sorts route config given a baseURL 1`] = `
 ]
 `;
 
-exports[`sortConfig sorts route config recursively 1`] = `
+exports[`sortRoutes sorts route config recursively 1`] = `
+[
+  {
+    "component": "",
+    "exact": true,
+    "path": "/some/page",
+  },
+  {
+    "component": "",
+    "path": "/docs",
+    "routes": [
+      {
+        "component": "",
+        "exact": true,
+        "path": "/docs/tags",
+      },
+      {
+        "component": "",
+        "exact": true,
+        "path": "/docs/tags/someTag",
+      },
+      {
+        "component": "",
+        "path": "/docs",
+        "routes": [
+          {
+            "component": "",
+            "exact": true,
+            "path": "/docs/doc1",
+          },
+          {
+            "component": "",
+            "exact": true,
+            "path": "/docs/doc2",
+          },
+        ],
+      },
+    ],
+  },
+]
+`;
+
+exports[`sortRoutes sorts route config correctly 1`] = `
+[
+  {
+    "component": "",
+    "path": "/community",
+  },
+  {
+    "component": "",
+    "path": "/some-page",
+  },
+  {
+    "component": "",
+    "path": "/docs",
+    "routes": [
+      {
+        "component": "",
+        "path": "/docs/someDoc",
+      },
+      {
+        "component": "",
+        "path": "/docs/someOtherDoc",
+      },
+    ],
+  },
+  {
+    "component": "",
+    "path": "/",
+  },
+  {
+    "component": "",
+    "path": "/",
+    "routes": [
+      {
+        "component": "",
+        "path": "/someDoc",
+      },
+      {
+        "component": "",
+        "path": "/someOtherDoc",
+      },
+    ],
+  },
+  {
+    "component": "",
+    "path": "/",
+    "routes": [
+      {
+        "component": "",
+        "path": "/subroute",
+      },
+    ],
+  },
+]
+`;
+
+exports[`sortRoutes sorts route config given a baseURL 1`] = `
+[
+  {
+    "component": "",
+    "path": "/latest/community",
+  },
+  {
+    "component": "",
+    "path": "/latest/example",
+  },
+  {
+    "component": "",
+    "path": "/latest/some-page",
+  },
+  {
+    "component": "",
+    "path": "/latest/docs",
+    "routes": [
+      {
+        "component": "",
+        "path": "/latest/docs/someDoc",
+      },
+      {
+        "component": "",
+        "path": "/latest/docs/someOtherDoc",
+      },
+    ],
+  },
+  {
+    "component": "",
+    "path": "/latest/",
+  },
+  {
+    "component": "",
+    "path": "/latest/",
+    "routes": [
+      {
+        "component": "",
+        "path": "/latest/someDoc",
+      },
+      {
+        "component": "",
+        "path": "/latest/someOtherDoc",
+      },
+    ],
+  },
+]
+`;
+
+exports[`sortRoutes sorts route config recursively 1`] = `
 [
   {
     "component": "",
diff --git a/packages/docusaurus/src/server/plugins/__tests__/init.test.ts b/packages/docusaurus/src/server/plugins/__tests__/init.test.ts
index 4e07fb686def..6cbb8af06c3d 100644
--- a/packages/docusaurus/src/server/plugins/__tests__/init.test.ts
+++ b/packages/docusaurus/src/server/plugins/__tests__/init.test.ts
@@ -7,11 +7,11 @@
 
 import path from 'path';
 
-import {loadContext, type LoadContextOptions} from '../../index';
+import {loadContext, type LoadContextParams} from '../../site';
 import {initPlugins} from '../init';
 
 describe('initPlugins', () => {
-  async function loadSite(options: Omit<LoadContextOptions, 'siteDir'> = {}) {
+  async function loadSite(options: Omit<LoadContextParams, 'siteDir'> = {}) {
     const siteDir = path.join(__dirname, '__fixtures__', 'site-with-plugin');
     const context = await loadContext({...options, siteDir});
     const plugins = await initPlugins(context);
diff --git a/packages/docusaurus/src/server/plugins/__tests__/index.test.ts b/packages/docusaurus/src/server/plugins/__tests__/plugins.test.ts
similarity index 97%
rename from packages/docusaurus/src/server/plugins/__tests__/index.test.ts
rename to packages/docusaurus/src/server/plugins/__tests__/plugins.test.ts
index 0ace57b22cd9..7729ef2bd05a 100644
--- a/packages/docusaurus/src/server/plugins/__tests__/index.test.ts
+++ b/packages/docusaurus/src/server/plugins/__tests__/plugins.test.ts
@@ -6,7 +6,7 @@
  */
 
 import path from 'path';
-import {loadPlugins} from '..';
+import {loadPlugins} from '../plugins';
 import type {Plugin, Props} from '@docusaurus/types';
 
 describe('loadPlugins', () => {
diff --git a/packages/docusaurus/src/server/plugins/__tests__/routeConfig.test.ts b/packages/docusaurus/src/server/plugins/__tests__/routeConfig.test.ts
index 64c8034eb520..da4345add7bb 100644
--- a/packages/docusaurus/src/server/plugins/__tests__/routeConfig.test.ts
+++ b/packages/docusaurus/src/server/plugins/__tests__/routeConfig.test.ts
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {applyRouteTrailingSlash, sortConfig} from '../routeConfig';
+import {applyRouteTrailingSlash, sortRoutes} from '../routeConfig';
 import type {RouteConfig} from '@docusaurus/types';
 import type {ApplyTrailingSlashParams} from '@docusaurus/utils-common';
 
@@ -164,7 +164,7 @@ describe('applyRouteTrailingSlash', () => {
   });
 });
 
-describe('sortConfig', () => {
+describe('sortRoutes', () => {
   it('sorts route config correctly', () => {
     const routes: RouteConfig[] = [
       {
@@ -202,7 +202,7 @@ describe('sortConfig', () => {
       },
     ];
 
-    sortConfig(routes);
+    sortRoutes(routes);
 
     expect(routes).toMatchSnapshot();
   });
@@ -248,7 +248,7 @@ describe('sortConfig', () => {
       },
     ];
 
-    sortConfig(routes);
+    sortRoutes(routes);
 
     expect(routes).toMatchSnapshot();
   });
@@ -290,7 +290,7 @@ describe('sortConfig', () => {
       },
     ];
 
-    sortConfig(routes, baseURL);
+    sortRoutes(routes, baseURL);
 
     expect(routes).toMatchSnapshot();
   });
diff --git a/packages/docusaurus/src/server/plugins/index.ts b/packages/docusaurus/src/server/plugins/index.ts
deleted file mode 100644
index 73fba212b289..000000000000
--- a/packages/docusaurus/src/server/plugins/index.ts
+++ /dev/null
@@ -1,153 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import path from 'path';
-import _ from 'lodash';
-import {docuHash, generate} from '@docusaurus/utils';
-import {initPlugins} from './init';
-import {createBootstrapPlugin, createMDXFallbackPlugin} from './synthetic';
-import {localizePluginTranslationFile} from '../translations/translations';
-import {applyRouteTrailingSlash, sortConfig} from './routeConfig';
-import type {
-  LoadContext,
-  PluginContentLoadedActions,
-  RouteConfig,
-  AllContent,
-  GlobalData,
-  LoadedPlugin,
-  InitializedPlugin,
-  PluginRouteContext,
-} from '@docusaurus/types';
-
-/**
- * Initializes the plugins, runs `loadContent`, `translateContent`,
- * `contentLoaded`, and `translateThemeConfig`. Because `contentLoaded` is
- * side-effect-ful (it generates temp files), so is this function. This function
- * would also mutate `context.siteConfig.themeConfig` to translate it.
- */
-export async function loadPlugins(context: LoadContext): Promise<{
-  plugins: LoadedPlugin[];
-  pluginsRouteConfigs: RouteConfig[];
-  globalData: GlobalData;
-}> {
-  // 1. Plugin Lifecycle - Initialization/Constructor.
-  const plugins: InitializedPlugin[] = await initPlugins(context);
-
-  plugins.push(
-    createBootstrapPlugin(context),
-    createMDXFallbackPlugin(context),
-  );
-
-  // 2. Plugin Lifecycle - loadContent.
-  // Currently plugins run lifecycle methods in parallel and are not
-  // order-dependent. We could change this in future if there are plugins which
-  // need to run in certain order or depend on others for data.
-  // This would also translate theme config and content upfront, given the
-  // translation files that the plugin declares.
-  const loadedPlugins: LoadedPlugin[] = await Promise.all(
-    plugins.map(async (plugin) => {
-      const content = await plugin.loadContent?.();
-      const rawTranslationFiles =
-        (await plugin.getTranslationFiles?.({content})) ?? [];
-      const translationFiles = await Promise.all(
-        rawTranslationFiles.map((translationFile) =>
-          localizePluginTranslationFile({
-            localizationDir: context.localizationDir,
-            translationFile,
-            plugin,
-          }),
-        ),
-      );
-      const translatedContent =
-        plugin.translateContent?.({content, translationFiles}) ?? content;
-      const translatedThemeConfigSlice = plugin.translateThemeConfig?.({
-        themeConfig: context.siteConfig.themeConfig,
-        translationFiles,
-      });
-      // Side-effect to merge theme config translations. A plugin should only
-      // translate its own slice of theme config and should make no assumptions
-      // about other plugins' keys, so this is safe to run in parallel.
-      Object.assign(context.siteConfig.themeConfig, translatedThemeConfigSlice);
-      return {...plugin, content: translatedContent};
-    }),
-  );
-
-  const allContent: AllContent = _.chain(loadedPlugins)
-    .groupBy((item) => item.name)
-    .mapValues((nameItems) =>
-      _.chain(nameItems)
-        .groupBy((item) => item.options.id)
-        .mapValues((idItems) => idItems[0]!.content)
-        .value(),
-    )
-    .value();
-
-  // 3. Plugin Lifecycle - contentLoaded.
-  const pluginsRouteConfigs: RouteConfig[] = [];
-  const globalData: GlobalData = {};
-
-  await Promise.all(
-    loadedPlugins.map(async ({content, ...plugin}) => {
-      if (!plugin.contentLoaded) {
-        return;
-      }
-      const pluginId = plugin.options.id;
-      // Plugins data files are namespaced by pluginName/pluginId
-      const dataDir = path.join(
-        context.generatedFilesDir,
-        plugin.name,
-        pluginId,
-      );
-      const pluginRouteContextModulePath = path.join(
-        dataDir,
-        `${docuHash('pluginRouteContextModule')}.json`,
-      );
-      const pluginRouteContext: PluginRouteContext['plugin'] = {
-        name: plugin.name,
-        id: pluginId,
-      };
-      await generate(
-        '/',
-        pluginRouteContextModulePath,
-        JSON.stringify(pluginRouteContext, null, 2),
-      );
-      const actions: PluginContentLoadedActions = {
-        addRoute(initialRouteConfig) {
-          // Trailing slash behavior is handled generically for all plugins
-          const finalRouteConfig = applyRouteTrailingSlash(
-            initialRouteConfig,
-            context.siteConfig,
-          );
-          pluginsRouteConfigs.push({
-            ...finalRouteConfig,
-            context: {
-              ...(finalRouteConfig.context && {data: finalRouteConfig.context}),
-              plugin: pluginRouteContextModulePath,
-            },
-          });
-        },
-        async createData(name, data) {
-          const modulePath = path.join(dataDir, name);
-          await generate(dataDir, name, data);
-          return modulePath;
-        },
-        setGlobalData(data) {
-          globalData[plugin.name] ??= {};
-          globalData[plugin.name]![pluginId] = data;
-        },
-      };
-
-      await plugin.contentLoaded({content, actions, allContent});
-    }),
-  );
-
-  // Sort the route config. This ensures that route with nested
-  // routes are always placed last.
-  sortConfig(pluginsRouteConfigs, context.siteConfig.baseUrl);
-
-  return {plugins: loadedPlugins, pluginsRouteConfigs, globalData};
-}
diff --git a/packages/docusaurus/src/server/plugins/plugins.ts b/packages/docusaurus/src/server/plugins/plugins.ts
new file mode 100644
index 000000000000..b7cd7729c6c2
--- /dev/null
+++ b/packages/docusaurus/src/server/plugins/plugins.ts
@@ -0,0 +1,318 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import path from 'path';
+import _ from 'lodash';
+import {docuHash, generate} from '@docusaurus/utils';
+import logger from '@docusaurus/logger';
+import {initPlugins} from './init';
+import {createBootstrapPlugin, createMDXFallbackPlugin} from './synthetic';
+import {localizePluginTranslationFile} from '../translations/translations';
+import {applyRouteTrailingSlash, sortRoutes} from './routeConfig';
+import {PerfLogger} from '../../utils';
+import type {
+  LoadContext,
+  PluginContentLoadedActions,
+  RouteConfig,
+  AllContent,
+  GlobalData,
+  LoadedPlugin,
+  InitializedPlugin,
+  PluginRouteContext,
+} from '@docusaurus/types';
+import type {PluginIdentifier} from '@docusaurus/types/src/plugin';
+
+async function translatePlugin({
+  plugin,
+  context,
+}: {
+  plugin: LoadedPlugin;
+  context: LoadContext;
+}): Promise<LoadedPlugin> {
+  const {content} = plugin;
+
+  const rawTranslationFiles =
+    (await plugin.getTranslationFiles?.({content: plugin.content})) ?? [];
+
+  const translationFiles = await Promise.all(
+    rawTranslationFiles.map((translationFile) =>
+      localizePluginTranslationFile({
+        localizationDir: context.localizationDir,
+        translationFile,
+        plugin,
+      }),
+    ),
+  );
+
+  const translatedContent =
+    plugin.translateContent?.({content, translationFiles}) ?? content;
+
+  const translatedThemeConfigSlice = plugin.translateThemeConfig?.({
+    themeConfig: context.siteConfig.themeConfig,
+    translationFiles,
+  });
+
+  // TODO dangerous legacy, need to be refactored!
+  // Side-effect to merge theme config translations. A plugin should only
+  // translate its own slice of theme config and should make no assumptions
+  // about other plugins' keys, so this is safe to run in parallel.
+  Object.assign(context.siteConfig.themeConfig, translatedThemeConfigSlice);
+  return {...plugin, content: translatedContent};
+}
+
+async function executePluginLoadContent({
+  plugin,
+  context,
+}: {
+  plugin: InitializedPlugin;
+  context: LoadContext;
+}): Promise<LoadedPlugin> {
+  return PerfLogger.async(
+    `Plugin - loadContent - ${plugin.name}@${plugin.options.id}`,
+    async () => {
+      const content = await plugin.loadContent?.();
+      const loadedPlugin: LoadedPlugin = {...plugin, content};
+      return translatePlugin({plugin: loadedPlugin, context});
+    },
+  );
+}
+
+async function executePluginsLoadContent({
+  plugins,
+  context,
+}: {
+  plugins: InitializedPlugin[];
+  context: LoadContext;
+}) {
+  return PerfLogger.async(`Plugins - loadContent`, () =>
+    Promise.all(
+      plugins.map((plugin) => executePluginLoadContent({plugin, context})),
+    ),
+  );
+}
+
+function aggregateAllContent(loadedPlugins: LoadedPlugin[]): AllContent {
+  return _.chain(loadedPlugins)
+    .groupBy((item) => item.name)
+    .mapValues((nameItems) =>
+      _.chain(nameItems)
+        .groupBy((item) => item.options.id)
+        .mapValues((idItems) => idItems[0]!.content)
+        .value(),
+    )
+    .value();
+}
+
+// TODO refactor and make this side-effect-free
+//  If the function was pure, we could more easily compare previous/next values
+//  on site reloads, and bail-out of the reload process earlier
+//  createData() modules should rather be declarative
+async function executePluginContentLoaded({
+  plugin,
+  context,
+  allContent,
+}: {
+  plugin: LoadedPlugin;
+  context: LoadContext;
+  // TODO AllContent was injected to this lifecycle for the debug plugin
+  //  This is what permits to create the debug routes for all other plugins
+  //  This was likely a bad idea and prevents to start executing contentLoaded()
+  //  until all plugins have finished loading all the data
+  //  we'd rather remove this and find another way to implement the debug plugin
+  //  A possible solution: make it a core feature instead of a plugin?
+  allContent: AllContent;
+}): Promise<{routes: RouteConfig[]; globalData: unknown}> {
+  return PerfLogger.async(
+    `Plugins - contentLoaded - ${plugin.name}@${plugin.options.id}`,
+    async () => {
+      if (!plugin.contentLoaded) {
+        return {routes: [], globalData: undefined};
+      }
+
+      const pluginId = plugin.options.id;
+      // Plugins data files are namespaced by pluginName/pluginId
+      const dataDir = path.join(
+        context.generatedFilesDir,
+        plugin.name,
+        pluginId,
+      );
+      const pluginRouteContextModulePath = path.join(
+        dataDir,
+        `${docuHash('pluginRouteContextModule')}.json`,
+      );
+      const pluginRouteContext: PluginRouteContext['plugin'] = {
+        name: plugin.name,
+        id: pluginId,
+      };
+      await generate(
+        '/',
+        pluginRouteContextModulePath,
+        JSON.stringify(pluginRouteContext, null, 2),
+      );
+
+      const routes: RouteConfig[] = [];
+      let globalData: unknown;
+
+      const actions: PluginContentLoadedActions = {
+        addRoute(initialRouteConfig) {
+          // Trailing slash behavior is handled generically for all plugins
+          const finalRouteConfig = applyRouteTrailingSlash(
+            initialRouteConfig,
+            context.siteConfig,
+          );
+          routes.push({
+            ...finalRouteConfig,
+            context: {
+              ...(finalRouteConfig.context && {data: finalRouteConfig.context}),
+              plugin: pluginRouteContextModulePath,
+            },
+          });
+        },
+        async createData(name, data) {
+          const modulePath = path.join(dataDir, name);
+          await generate(dataDir, name, data);
+          return modulePath;
+        },
+        setGlobalData(data) {
+          globalData = data;
+        },
+      };
+
+      await plugin.contentLoaded({
+        content: plugin.content,
+        actions,
+        allContent,
+      });
+
+      return {routes, globalData};
+    },
+  );
+}
+
+async function executePluginsContentLoaded({
+  plugins,
+  context,
+}: {
+  plugins: LoadedPlugin[];
+  context: LoadContext;
+}): Promise<{routes: RouteConfig[]; globalData: GlobalData}> {
+  return PerfLogger.async(`Plugins - contentLoaded`, async () => {
+    const allContent = aggregateAllContent(plugins);
+
+    const routes: RouteConfig[] = [];
+    const globalData: GlobalData = {};
+
+    await Promise.all(
+      plugins.map(async (plugin) => {
+        const {routes: pluginRoutes, globalData: pluginGlobalData} =
+          await executePluginContentLoaded({
+            plugin,
+            context,
+            allContent,
+          });
+
+        routes.push(...pluginRoutes);
+
+        if (pluginGlobalData !== undefined) {
+          globalData[plugin.name] ??= {};
+          globalData[plugin.name]![plugin.options.id] = pluginGlobalData;
+        }
+      }),
+    );
+
+    // Sort the route config.
+    // This ensures that route with sub routes are always placed last.
+    sortRoutes(routes, context.siteConfig.baseUrl);
+
+    return {routes, globalData};
+  });
+}
+
+export type LoadPluginsResult = {
+  plugins: LoadedPlugin[];
+  routes: RouteConfig[];
+  globalData: GlobalData;
+};
+
+/**
+ * Initializes the plugins, runs `loadContent`, `translateContent`,
+ * `contentLoaded`, and `translateThemeConfig`. Because `contentLoaded` is
+ * side-effect-ful (it generates temp files), so is this function. This function
+ * would also mutate `context.siteConfig.themeConfig` to translate it.
+ */
+export async function loadPlugins(
+  context: LoadContext,
+): Promise<LoadPluginsResult> {
+  return PerfLogger.async('Plugins - loadPlugins', async () => {
+    // 1. Plugin Lifecycle - Initialization/Constructor.
+    const plugins: InitializedPlugin[] = await PerfLogger.async(
+      'Plugins - initPlugins',
+      () => initPlugins(context),
+    );
+
+    plugins.push(
+      createBootstrapPlugin(context),
+      createMDXFallbackPlugin(context),
+    );
+
+    // 2. Plugin Lifecycle - loadContent.
+    const loadedPlugins = await executePluginsLoadContent({plugins, context});
+
+    // 3. Plugin Lifecycle - contentLoaded.
+    const {routes, globalData} = await executePluginsContentLoaded({
+      plugins: loadedPlugins,
+      context,
+    });
+
+    return {plugins: loadedPlugins, routes, globalData};
+  });
+}
+
+export function getPluginByIdentifier({
+  plugins,
+  pluginIdentifier,
+}: {
+  pluginIdentifier: PluginIdentifier;
+  plugins: LoadedPlugin[];
+}): LoadedPlugin {
+  const plugin = plugins.find(
+    (p) =>
+      p.name === pluginIdentifier.name && p.options.id === pluginIdentifier.id,
+  );
+  if (!plugin) {
+    throw new Error(
+      logger.interpolate`Plugin not found for identifier ${pluginIdentifier.name}@${pluginIdentifier.id}`,
+    );
+  }
+  return plugin;
+}
+
+export async function reloadPlugin({
+  pluginIdentifier,
+  plugins,
+  context,
+}: {
+  pluginIdentifier: PluginIdentifier;
+  plugins: LoadedPlugin[];
+  context: LoadContext;
+}): Promise<LoadPluginsResult> {
+  return PerfLogger.async('Plugins - reloadPlugin', async () => {
+    const plugin = getPluginByIdentifier({plugins, pluginIdentifier});
+
+    const reloadedPlugin = await executePluginLoadContent({plugin, context});
+    const newPlugins = plugins.with(plugins.indexOf(plugin), reloadedPlugin);
+
+    // Unfortunately, due to the "AllContent" data we have to re-execute this
+    // for all plugins, not just the one to reload...
+    const {routes, globalData} = await executePluginsContentLoaded({
+      plugins: newPlugins,
+      context,
+    });
+
+    return {plugins: newPlugins, routes, globalData};
+  });
+}
diff --git a/packages/docusaurus/src/server/plugins/routeConfig.ts b/packages/docusaurus/src/server/plugins/routeConfig.ts
index d757406bd09b..cd824f1f4ba6 100644
--- a/packages/docusaurus/src/server/plugins/routeConfig.ts
+++ b/packages/docusaurus/src/server/plugins/routeConfig.ts
@@ -27,7 +27,7 @@ export function applyRouteTrailingSlash(
   };
 }
 
-export function sortConfig(
+export function sortRoutes(
   routeConfigs: RouteConfig[],
   baseUrl: string = '/',
 ): void {
@@ -64,7 +64,7 @@ export function sortConfig(
 
   routeConfigs.forEach((routeConfig) => {
     if (routeConfig.routes) {
-      sortConfig(routeConfig.routes, baseUrl);
+      sortRoutes(routeConfig.routes, baseUrl);
     }
   });
 }
diff --git a/packages/docusaurus/src/server/routes.ts b/packages/docusaurus/src/server/routes.ts
index 907f77816b8f..95621d34dab3 100644
--- a/packages/docusaurus/src/server/routes.ts
+++ b/packages/docusaurus/src/server/routes.ts
@@ -5,210 +5,26 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import query from 'querystring';
-import _ from 'lodash';
 import logger from '@docusaurus/logger';
-import {
-  docuHash,
-  normalizeUrl,
-  simpleHash,
-  escapePath,
-} from '@docusaurus/utils';
-import {getAllFinalRoutes} from './utils';
-import type {
-  Module,
-  RouteConfig,
-  RouteModules,
-  ChunkNames,
-  RouteChunkNames,
-  ReportingSeverity,
-} from '@docusaurus/types';
+import {normalizeUrl} from '@docusaurus/utils';
+import type {RouteConfig, ReportingSeverity} from '@docusaurus/types';
 
-type LoadedRoutes = {
-  /** Serialized routes config that can be directly emitted into temp file. */
-  routesConfig: string;
-  /** @see {ChunkNames} */
-  routesChunkNames: RouteChunkNames;
-  /**
-   * A map from chunk name to module paths. Module paths would have backslash
-   * escaped already, so they can be directly printed.
-   */
-  registry: {
-    [chunkName: string]: string;
-  };
-  /**
-   * Collect all page paths for injecting it later in the plugin lifecycle.
-   * This is useful for plugins like sitemaps, redirects etc... Only collects
-   * "actual" pages, i.e. those without subroutes, because if a route has
-   * subroutes, it is probably a wrapper.
-   */
-  routesPaths: string[];
-};
-
-/** Indents every line of `str` by one level. */
-function indent(str: string) {
-  return `  ${str.replace(/\n/g, `\n  `)}`;
-}
-
-const chunkNameCache = new Map<string, string>();
-const chunkNameCount = new Map<string, number>();
-
-/**
- * Generates a unique chunk name that can be used in the chunk registry.
- *
- * @param modulePath A path to generate chunk name from. The actual value has no
- * semantic significance.
- * @param prefix A prefix to append to the chunk name, to avoid name clash.
- * @param preferredName Chunk names default to `modulePath`, and this can supply
- * a more human-readable name.
- * @param shortId When `true`, the chunk name would only be a hash without any
- * other characters. Useful for bundle size. Defaults to `true` in production.
- */
-export function genChunkName(
-  modulePath: string,
-  prefix?: string,
-  preferredName?: string,
-  shortId: boolean = process.env.NODE_ENV === 'production',
-): string {
-  let chunkName = chunkNameCache.get(modulePath);
-  if (!chunkName) {
-    if (shortId) {
-      chunkName = simpleHash(modulePath, 8);
-    } else {
-      let str = modulePath;
-      if (preferredName) {
-        const shortHash = simpleHash(modulePath, 3);
-        str = `${preferredName}${shortHash}`;
-      }
-      const name = docuHash(str);
-      chunkName = prefix ? `${prefix}---${name}` : name;
-    }
-    const seenCount = (chunkNameCount.get(chunkName) ?? 0) + 1;
-    if (seenCount > 1) {
-      chunkName += seenCount.toString(36);
-    }
-    chunkNameCache.set(modulePath, chunkName);
-    chunkNameCount.set(chunkName, seenCount);
-  }
-  return chunkName;
-}
-
-/**
- * Takes a piece of route config, and serializes it into raw JS code. The shape
- * is the same as react-router's `RouteConfig`. Formatting is similar to
- * `JSON.stringify` but without all the quotes.
- */
-function serializeRouteConfig({
-  routePath,
-  routeHash,
-  exact,
-  subroutesCodeStrings,
-  props,
-}: {
-  routePath: string;
-  routeHash: string;
-  exact?: boolean;
-  subroutesCodeStrings?: string[];
-  props: {[propName: string]: unknown};
-}) {
-  const parts = [
-    `path: '${routePath}'`,
-    `component: ComponentCreator('${routePath}', '${routeHash}')`,
-  ];
-
-  if (exact) {
-    parts.push(`exact: true`);
-  }
-
-  if (subroutesCodeStrings) {
-    parts.push(
-      `routes: [
-${indent(subroutesCodeStrings.join(',\n'))}
-]`,
-    );
-  }
-
-  Object.entries(props).forEach(([propName, propValue]) => {
-    const isIdentifier =
-      /^[$_\p{ID_Start}][$\u200c\u200d\p{ID_Continue}]*$/u.test(propName);
-    const key = isIdentifier ? propName : JSON.stringify(propName);
-    parts.push(`${key}: ${JSON.stringify(propValue)}`);
-  });
-
-  return `{
-${indent(parts.join(',\n'))}
-}`;
-}
-
-const isModule = (value: unknown): value is Module =>
-  typeof value === 'string' ||
-  (typeof value === 'object' &&
-    // eslint-disable-next-line no-underscore-dangle
-    !!(value as {[key: string]: unknown} | null)?.__import);
-
-/**
- * Takes a {@link Module} (which is nothing more than a path plus some metadata
- * like query) and returns the string path it represents.
- */
-function getModulePath(target: Module): string {
-  if (typeof target === 'string') {
-    return target;
+// Recursively get the final routes (routes with no subroutes)
+export function getAllFinalRoutes(routeConfig: RouteConfig[]): RouteConfig[] {
+  function getFinalRoutes(route: RouteConfig): RouteConfig[] {
+    return route.routes ? route.routes.flatMap(getFinalRoutes) : [route];
   }
-  const queryStr = target.query ? `?${query.stringify(target.query)}` : '';
-  return `${target.path}${queryStr}`;
-}
-
-/**
- * Takes a route module (which is a tree of modules), and transforms each module
- * into a chunk name. It also mutates `res.registry` and registers the loaders
- * for each chunk.
- *
- * @param routeModule One route module to be transformed.
- * @param prefix Prefix passed to {@link genChunkName}.
- * @param name Preferred name passed to {@link genChunkName}.
- * @param res The route structures being loaded.
- */
-function genChunkNames(
-  routeModule: RouteModules,
-  prefix: string,
-  name: string,
-  res: LoadedRoutes,
-): ChunkNames;
-function genChunkNames(
-  routeModule: RouteModules | RouteModules[] | Module,
-  prefix: string,
-  name: string,
-  res: LoadedRoutes,
-): ChunkNames | ChunkNames[] | string;
-function genChunkNames(
-  routeModule: RouteModules | RouteModules[] | Module,
-  prefix: string,
-  name: string,
-  res: LoadedRoutes,
-): string | ChunkNames | ChunkNames[] {
-  if (isModule(routeModule)) {
-    // This is a leaf node, no need to recurse
-    const modulePath = getModulePath(routeModule);
-    const chunkName = genChunkName(modulePath, prefix, name);
-    res.registry[chunkName] = escapePath(modulePath);
-    return chunkName;
-  }
-  if (Array.isArray(routeModule)) {
-    return routeModule.map((val, index) =>
-      genChunkNames(val, `${index}`, name, res),
-    );
-  }
-  return _.mapValues(routeModule, (v, key) => genChunkNames(v, key, name, res));
+  return routeConfig.flatMap(getFinalRoutes);
 }
 
 export function handleDuplicateRoutes(
-  pluginsRouteConfigs: RouteConfig[],
+  routes: RouteConfig[],
   onDuplicateRoutes: ReportingSeverity,
 ): void {
   if (onDuplicateRoutes === 'ignore') {
     return;
   }
-  const allRoutes: string[] = getAllFinalRoutes(pluginsRouteConfigs).map(
+  const allRoutes: string[] = getAllFinalRoutes(routes).map(
     (routeConfig) => routeConfig.path,
   );
   const seenRoutes = new Set<string>();
@@ -230,52 +46,6 @@ This could lead to non-deterministic routing behavior.`;
   }
 }
 
-/**
- * This is the higher level overview of route code generation. For each route
- * config node, it returns the node's serialized form, and mutates `registry`,
- * `routesPaths`, and `routesChunkNames` accordingly.
- */
-function genRouteCode(routeConfig: RouteConfig, res: LoadedRoutes): string {
-  const {
-    path: routePath,
-    component,
-    modules = {},
-    context,
-    routes: subroutes,
-    priority,
-    exact,
-    ...props
-  } = routeConfig;
-
-  if (typeof routePath !== 'string' || !component) {
-    throw new Error(
-      `Invalid route config: path must be a string and component is required.
-${JSON.stringify(routeConfig)}`,
-    );
-  }
-
-  if (!subroutes) {
-    res.routesPaths.push(routePath);
-  }
-
-  const routeHash = simpleHash(JSON.stringify(routeConfig), 3);
-  res.routesChunkNames[`${routePath}-${routeHash}`] = {
-    // Avoid clash with a prop called "component"
-    ...genChunkNames({__comp: component}, 'component', component, res),
-    ...(context &&
-      genChunkNames({__context: context}, 'context', routePath, res)),
-    ...genChunkNames(modules, 'module', routePath, res),
-  };
-
-  return serializeRouteConfig({
-    routePath: routePath.replace(/'/g, "\\'"),
-    routeHash,
-    subroutesCodeStrings: subroutes?.map((r) => genRouteCode(r, res)),
-    exact,
-    props,
-  });
-}
-
 /**
  * Old stuff
  * As far as I understand, this is what permits to SSG the 404.html file
@@ -285,45 +55,12 @@ ${JSON.stringify(routeConfig)}`,
  */
 const NotFoundRoutePath = '/404.html';
 
-/**
- * Routes are prepared into three temp files:
- *
- * - `routesConfig`, the route config passed to react-router. This file is kept
- * minimal, because it can't be code-splitted.
- * - `routesChunkNames`, a mapping from route paths (hashed) to code-splitted
- * chunk names.
- * - `registry`, a mapping from chunk names to options for react-loadable.
- */
-export function loadRoutes(
+export function getRoutesPaths(
   routeConfigs: RouteConfig[],
   baseUrl: string,
-  onDuplicateRoutes: ReportingSeverity,
-): LoadedRoutes {
-  handleDuplicateRoutes(routeConfigs, onDuplicateRoutes);
-  const res: LoadedRoutes = {
-    // To be written by `genRouteCode`
-    routesConfig: '',
-    routesChunkNames: {},
-    registry: {},
-    routesPaths: [normalizeUrl([baseUrl, NotFoundRoutePath])],
-  };
-
-  // `genRouteCode` would mutate `res`
-  const routeConfigSerialized = routeConfigs
-    .map((r) => genRouteCode(r, res))
-    .join(',\n');
-
-  res.routesConfig = `import React from 'react';
-import ComponentCreator from '@docusaurus/ComponentCreator';
-
-export default [
-${indent(routeConfigSerialized)},
-  {
-    path: '*',
-    component: ComponentCreator('*'),
-  },
-];
-`;
-
-  return res;
+): string[] {
+  return [
+    normalizeUrl([baseUrl, NotFoundRoutePath]),
+    ...getAllFinalRoutes(routeConfigs).map((r) => r.path),
+  ];
 }
diff --git a/packages/docusaurus/src/server/site.ts b/packages/docusaurus/src/server/site.ts
new file mode 100644
index 000000000000..a5148781f92f
--- /dev/null
+++ b/packages/docusaurus/src/server/site.ts
@@ -0,0 +1,276 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import path from 'path';
+import {
+  localizePath,
+  DEFAULT_BUILD_DIR_NAME,
+  GENERATED_FILES_DIR_NAME,
+} from '@docusaurus/utils';
+import combinePromises from 'combine-promises';
+import {loadSiteConfig} from './config';
+import {loadClientModules} from './clientModules';
+import {loadPlugins, reloadPlugin} from './plugins/plugins';
+import {loadHtmlTags} from './htmlTags';
+import {loadSiteMetadata} from './siteMetadata';
+import {loadI18n} from './i18n';
+import {
+  loadSiteCodeTranslations,
+  getPluginsDefaultCodeTranslationMessages,
+} from './translations/translations';
+import {PerfLogger} from '../utils';
+import {generateSiteFiles} from './codegen/codegen';
+import {getRoutesPaths, handleDuplicateRoutes} from './routes';
+import type {LoadPluginsResult} from './plugins/plugins';
+import type {
+  DocusaurusConfig,
+  GlobalData,
+  LoadContext,
+  Props,
+} from '@docusaurus/types';
+import type {PluginIdentifier} from '@docusaurus/types/src/plugin';
+
+export type LoadContextParams = {
+  /** Usually the CWD; can be overridden with command argument. */
+  siteDir: string;
+  /** Custom output directory. Can be customized with `--out-dir` option */
+  outDir?: string;
+  /** Custom config path. Can be customized with `--config` option */
+  config?: string;
+  /** Default is `i18n.defaultLocale` */
+  locale?: string;
+  /**
+   * `true` means the paths will have the locale prepended; `false` means they
+   * won't (useful for `yarn build -l zh-Hans` where the output should be
+   * emitted into `build/` instead of `build/zh-Hans/`); `undefined` is like the
+   * "smart" option where only non-default locale paths are localized
+   */
+  localizePath?: boolean;
+};
+
+export type LoadSiteParams = LoadContextParams;
+
+export type Site = {
+  props: Props;
+  params: LoadSiteParams;
+};
+
+/**
+ * Loading context is the very first step in site building. Its params are
+ * directly acquired from CLI options. It mainly loads `siteConfig` and the i18n
+ * context (which includes code translations). The `LoadContext` will be passed
+ * to plugin constructors.
+ */
+export async function loadContext(
+  params: LoadContextParams,
+): Promise<LoadContext> {
+  const {
+    siteDir,
+    outDir: baseOutDir = DEFAULT_BUILD_DIR_NAME,
+    locale,
+    config: customConfigFilePath,
+  } = params;
+  const generatedFilesDir = path.resolve(siteDir, GENERATED_FILES_DIR_NAME);
+
+  const {siteConfig: initialSiteConfig, siteConfigPath} = await loadSiteConfig({
+    siteDir,
+    customConfigFilePath,
+  });
+
+  const i18n = await loadI18n(initialSiteConfig, {locale});
+
+  const baseUrl = localizePath({
+    path: initialSiteConfig.baseUrl,
+    i18n,
+    options: params,
+    pathType: 'url',
+  });
+  const outDir = localizePath({
+    path: path.resolve(siteDir, baseOutDir),
+    i18n,
+    options: params,
+    pathType: 'fs',
+  });
+  const localizationDir = path.resolve(
+    siteDir,
+    i18n.path,
+    i18n.localeConfigs[i18n.currentLocale]!.path,
+  );
+
+  const siteConfig: DocusaurusConfig = {...initialSiteConfig, baseUrl};
+
+  const codeTranslations = await loadSiteCodeTranslations({localizationDir});
+
+  return {
+    siteDir,
+    generatedFilesDir,
+    localizationDir,
+    siteConfig,
+    siteConfigPath,
+    outDir,
+    baseUrl,
+    i18n,
+    codeTranslations,
+  };
+}
+
+async function createSiteProps(
+  params: LoadPluginsResult & {context: LoadContext},
+): Promise<Props> {
+  const {plugins, routes, context} = params;
+  const {
+    generatedFilesDir,
+    siteDir,
+    siteConfig,
+    siteConfigPath,
+    outDir,
+    baseUrl,
+    i18n,
+    localizationDir,
+    codeTranslations: siteCodeTranslations,
+  } = context;
+
+  const {headTags, preBodyTags, postBodyTags} = loadHtmlTags(plugins);
+
+  const {codeTranslations, siteMetadata} = await combinePromises({
+    // TODO code translations should be loaded as part of LoadedPlugin?
+    codeTranslations: PerfLogger.async(
+      'Load - loadCodeTranslations',
+      async () => ({
+        ...(await getPluginsDefaultCodeTranslationMessages(plugins)),
+        ...siteCodeTranslations,
+      }),
+    ),
+    siteMetadata: PerfLogger.async('Load - loadSiteMetadata', () =>
+      loadSiteMetadata({plugins, siteDir}),
+    ),
+  });
+
+  handleDuplicateRoutes(routes, siteConfig.onDuplicateRoutes);
+  const routesPaths = getRoutesPaths(routes, baseUrl);
+
+  return {
+    siteConfig,
+    siteConfigPath,
+    siteMetadata,
+    siteDir,
+    outDir,
+    baseUrl,
+    i18n,
+    localizationDir,
+    generatedFilesDir,
+    routes,
+    routesPaths,
+    plugins,
+    headTags,
+    preBodyTags,
+    postBodyTags,
+    codeTranslations,
+  };
+}
+
+// TODO global data should be part of site props?
+async function createSiteFiles({
+  site,
+  globalData,
+}: {
+  site: Site;
+  globalData: GlobalData;
+}) {
+  return PerfLogger.async('Load - createSiteFiles', async () => {
+    const {
+      props: {
+        plugins,
+        generatedFilesDir,
+        siteConfig,
+        siteMetadata,
+        i18n,
+        codeTranslations,
+        routes,
+        baseUrl,
+      },
+    } = site;
+    const clientModules = loadClientModules(plugins);
+    await generateSiteFiles({
+      generatedFilesDir,
+      clientModules,
+      siteConfig,
+      siteMetadata,
+      i18n,
+      codeTranslations,
+      globalData,
+      routes,
+      baseUrl,
+    });
+  });
+}
+
+/**
+ * This is the crux of the Docusaurus server-side. It reads everything it needs—
+ * code translations, config file, plugin modules... Plugins then use their
+ * lifecycles to generate content and other data. It is side-effect-ful because
+ * it generates temp files in the `.docusaurus` folder for the bundler.
+ */
+export async function loadSite(params: LoadContextParams): Promise<Site> {
+  PerfLogger.start('Load - loadContext');
+  const context = await loadContext(params);
+  PerfLogger.end('Load - loadContext');
+
+  PerfLogger.start('Load - loadPlugins');
+  const {plugins, routes, globalData} = await loadPlugins(context);
+  PerfLogger.end('Load - loadPlugins');
+
+  const props = await createSiteProps({plugins, routes, globalData, context});
+
+  const site: Site = {props, params};
+
+  await createSiteFiles({
+    site,
+    globalData,
+  });
+
+  return site;
+}
+
+export async function reloadSite(site: Site): Promise<Site> {
+  // TODO this can be optimized, for example:
+  //  - plugins loading same data as before should not recreate routes/bundles
+  //  - codegen does not need to re-run if nothing changed
+  return loadSite(site.params);
+}
+
+export async function reloadSitePlugin(
+  site: Site,
+  pluginIdentifier: PluginIdentifier,
+): Promise<Site> {
+  console.log(
+    `reloadSitePlugin ${pluginIdentifier.name}@${pluginIdentifier.id}`,
+  );
+
+  const {plugins, routes, globalData} = await reloadPlugin({
+    pluginIdentifier,
+    plugins: site.props.plugins,
+    context: site.props,
+  });
+
+  const newProps = await createSiteProps({
+    plugins,
+    routes,
+    globalData,
+    context: site.props, // Props extends Context
+  });
+
+  const newSite: Site = {
+    props: newProps,
+    params: site.params,
+  };
+
+  // TODO optimize, bypass useless codegen if new site is similar to old site
+  await createSiteFiles({site: newSite, globalData});
+
+  return newSite;
+}
diff --git a/packages/docusaurus/src/server/translations/translations.ts b/packages/docusaurus/src/server/translations/translations.ts
index 83d19495bffc..ceb4efc105ae 100644
--- a/packages/docusaurus/src/server/translations/translations.ts
+++ b/packages/docusaurus/src/server/translations/translations.ts
@@ -279,3 +279,15 @@ Please report this Docusaurus issue. name=${unusedDefaultCodeMessages}`;
     }),
   );
 }
+
+export async function loadSiteCodeTranslations({
+  localizationDir,
+}: {
+  localizationDir: string;
+}): Promise<CodeTranslations> {
+  const codeTranslationFileContent =
+    (await readCodeTranslationFileContent({localizationDir})) ?? {};
+
+  // We only need key->message for code translations
+  return _.mapValues(codeTranslationFileContent, (value) => value.message);
+}
diff --git a/packages/docusaurus/src/server/utils.ts b/packages/docusaurus/src/server/utils.ts
index e0e67454c7ea..d6c09dc468e1 100644
--- a/packages/docusaurus/src/server/utils.ts
+++ b/packages/docusaurus/src/server/utils.ts
@@ -7,15 +7,6 @@
 
 import path from 'path';
 import {posixPath, Globby} from '@docusaurus/utils';
-import type {RouteConfig} from '@docusaurus/types';
-
-// Recursively get the final routes (routes with no subroutes)
-export function getAllFinalRoutes(routeConfig: RouteConfig[]): RouteConfig[] {
-  function getFinalRoutes(route: RouteConfig): RouteConfig[] {
-    return route.routes ? route.routes.flatMap(getFinalRoutes) : [route];
-  }
-  return routeConfig.flatMap(getFinalRoutes);
-}
 
 // Globby that fix Windows path patterns
 // See https://github.com/facebook/docusaurus/pull/4222#issuecomment-795517329
diff --git a/packages/docusaurus/src/utils.ts b/packages/docusaurus/src/utils.ts
index 044e22d3fe70..9fe1c616a523 100644
--- a/packages/docusaurus/src/utils.ts
+++ b/packages/docusaurus/src/utils.ts
@@ -15,6 +15,10 @@ type PerfLoggerAPI = {
   start: (label: string) => void;
   end: (label: string) => void;
   log: (message: string) => void;
+  async: <Result>(
+    label: string,
+    asyncFn: () => Result | Promise<Result>,
+  ) => Promise<Result>;
 };
 
 function createPerfLogger(): PerfLoggerAPI {
@@ -24,14 +28,31 @@ function createPerfLogger(): PerfLoggerAPI {
       start: noop,
       end: noop,
       log: noop,
+      async: async (_label, asyncFn) => asyncFn(),
     };
   }
 
   const prefix = logger.yellow(`[PERF] `);
+
+  const start: PerfLoggerAPI['start'] = (label) => console.time(prefix + label);
+
+  const end: PerfLoggerAPI['end'] = (label) => console.timeEnd(prefix + label);
+
+  const log: PerfLoggerAPI['log'] = (label: string) =>
+    console.log(prefix + label);
+
+  const async: PerfLoggerAPI['async'] = async (label, asyncFn) => {
+    start(label);
+    const result = await asyncFn();
+    end(label);
+    return result;
+  };
+
   return {
-    start: (label) => console.time(prefix + label),
-    end: (label) => console.timeEnd(prefix + label),
-    log: (label) => console.log(prefix + label),
+    start,
+    end,
+    log,
+    async,
   };
 }
 
diff --git a/packages/docusaurus/src/webpack/__tests__/client.test.ts b/packages/docusaurus/src/webpack/__tests__/client.test.ts
index 19ba00193b69..20b8447fac0f 100644
--- a/packages/docusaurus/src/webpack/__tests__/client.test.ts
+++ b/packages/docusaurus/src/webpack/__tests__/client.test.ts
@@ -12,26 +12,42 @@ import {loadSetup} from '../../server/__tests__/testUtils';
 
 describe('webpack dev config', () => {
   it('simple start', async () => {
-    const props = await loadSetup('simple-site');
-    const {clientConfig} = await createStartClientConfig({props});
+    const {props} = await loadSetup('simple-site');
+    const {clientConfig} = await createStartClientConfig({
+      props,
+      minify: false,
+      poll: false,
+    });
     webpack.validate(clientConfig);
   });
 
   it('simple build', async () => {
-    const props = await loadSetup('simple-site');
-    const {config} = await createBuildClientConfig({props});
+    const {props} = await loadSetup('simple-site');
+    const {config} = await createBuildClientConfig({
+      props,
+      minify: false,
+      bundleAnalyzer: false,
+    });
     webpack.validate(config);
   });
 
   it('custom start', async () => {
-    const props = await loadSetup('custom-site');
-    const {clientConfig} = await createStartClientConfig({props});
+    const {props} = await loadSetup('custom-site');
+    const {clientConfig} = await createStartClientConfig({
+      props,
+      minify: false,
+      poll: false,
+    });
     webpack.validate(clientConfig);
   });
 
   it('custom build', async () => {
-    const props = await loadSetup('custom-site');
-    const {config} = await createBuildClientConfig({props});
+    const {props} = await loadSetup('custom-site');
+    const {config} = await createBuildClientConfig({
+      props,
+      minify: false,
+      bundleAnalyzer: false,
+    });
     webpack.validate(config);
   });
 });
diff --git a/packages/docusaurus/src/webpack/__tests__/server.test.ts b/packages/docusaurus/src/webpack/__tests__/server.test.ts
index 9eec2824fda5..5ef069861d5b 100644
--- a/packages/docusaurus/src/webpack/__tests__/server.test.ts
+++ b/packages/docusaurus/src/webpack/__tests__/server.test.ts
@@ -14,7 +14,7 @@ import {loadSetup} from '../../server/__tests__/testUtils';
 describe('webpack production config', () => {
   it('simple', async () => {
     jest.spyOn(console, 'log').mockImplementation(() => {});
-    const props = await loadSetup('simple-site');
+    const {props} = await loadSetup('simple-site');
     const {config} = await createServerConfig({
       props,
     });
@@ -23,7 +23,7 @@ describe('webpack production config', () => {
 
   it('custom', async () => {
     jest.spyOn(console, 'log').mockImplementation(() => {});
-    const props = await loadSetup('custom-site');
+    const {props} = await loadSetup('custom-site');
     const {config} = await createServerConfig({
       props,
     });
diff --git a/project-words.txt b/project-words.txt
index f3fd6a5256a2..b570a80a8e57 100644
--- a/project-words.txt
+++ b/project-words.txt
@@ -47,6 +47,8 @@ changefreq
 Chedeau
 chedeau
 Clément
+Codegen
+codegen
 codesandbox
 Codespaces
 commonmark
@@ -284,6 +286,8 @@ redwoodjs
 refactorings
 Rehype
 rehype
+Reloadable
+reloadable
 renderable
 REPONAME
 Retrocompatibility