Add Ledger team update for 2025-09-24

Author: lehins

blog/2025-09-24-ledger.md

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+---
+title: Ledger Team Update
+slug: 2025-09-24-ledger
+authors: lehins
+tags: [ledger]
+hide_table_of_contents: false
+---
+
+## High level summary
+
+This period Ledger team has implemented an improvement to withdrawals predicate failure reporting, that will become available with next intra-era hardfork. We've also experimented with a potential representation in Haskell for transaction levels relateed to CIP-118: sub-transactions vs top level transactions. Besides that we did some more code cleanup and made further improvements to the test suite.
+
+Aside from development work there was Ledger team presence at the Node Diversity workshop, which included relevant people from all of the alternative Node implementations that are currently under development.
+
+## Low level summary
+
+### Features
+
+* [PR-5281] - Added `FromJSON` instance for `PParamUpdates`
+* [PR-5291] - Move withdrawals to LEDGER PV 11 onwards
+* [PR-5297] - Remove UMap
+
+### Testing
+
+* [PR-5195] - Refactor some parts of cardano-ledger-conformance to prepare for Dijkstra
+* [PR-5288] - Update fls and fix conformance build
+* [PR-5289] - Add Dijkstra `CddlSpec`
+* [PR-5285] - Added a new test Plutus script
+* [PR-5280] - Small refactoring of `impSatisfyNativeScript` to avoid duplication
+* [PR-5293] - Enable epoch boundary hook in conformance
+* [PR-5303] - Migrate constrained-generators docs to its own repo
+
+### Infrastructure and releasing
+
+* [PR-5286] - Post release process changelog version bumps
+* [PR-5283] - Use the "union" merge driver for changelogs
+* [PR-5290] - Update version and CHANGELOG of `cardano-ledger-core`
+* [PR-5287] - Fixup random 1.3 compatibility
+* [PR-5307] - Fix CHANGELOG files
+
+[PR-5281]: https://github.com/IntersectMBO/cardano-ledger/pull/5281
+[PR-5195]: https://github.com/IntersectMBO/cardano-ledger/pull/5195
+[PR-5288]: https://github.com/IntersectMBO/cardano-ledger/pull/5288
+[PR-5286]: https://github.com/IntersectMBO/cardano-ledger/pull/5286
+[PR-5289]: https://github.com/IntersectMBO/cardano-ledger/pull/5289
+[PR-5285]: https://github.com/IntersectMBO/cardano-ledger/pull/5285
+[PR-5283]: https://github.com/IntersectMBO/cardano-ledger/pull/5283
+[PR-5290]: https://github.com/IntersectMBO/cardano-ledger/pull/5290
+[PR-5280]: https://github.com/IntersectMBO/cardano-ledger/pull/5280
+[PR-5287]: https://github.com/IntersectMBO/cardano-ledger/pull/5287
+[PR-5291]: https://github.com/IntersectMBO/cardano-ledger/pull/5291
+[PR-5293]: https://github.com/IntersectMBO/cardano-ledger/pull/5293
+[PR-5297]: https://github.com/IntersectMBO/cardano-ledger/pull/5297
+[PR-5303]: https://github.com/IntersectMBO/cardano-ledger/pull/5303
+[PR-5307]: https://github.com/IntersectMBO/cardano-ledger/pull/5307