Follow the setup steps for jekyll on your machine.
Run
$ bundle install
Add the
AIRTABLE_API_KEY environment variable.
Run
$ bundle exec jekyll serve
The "API" is a series of JSON files that are statically generated on the build set of the site. They don't change until the site is rebuilt.
The frontend is build with plain HTML, JS and CSS primarily. It uses the Vue (framework) and Leaflet (maps) libraries.