- Instrument `state` and `state_group` storage-related operations to better picture what's happening when tracing. ([\#15610](https://github.com/matrix-org/synapse/issues/15610), [\#15647](https://github.com/matrix-org/synapse/issues/15647))
- Instrument `state` and `state_group` storage-related operations to better picture what's happening when tracing. ([\#15610](https://github.com/matrix-org/synapse/issues/15610), [\#15647](https://github.com/matrix-org/synapse/issues/15647))
- Trace how many new events from the backfill response we need to process. ([\#15633](https://github.com/matrix-org/synapse/issues/15633))
- Trace how many new events from the backfill response we need to process. ([\#15633](https://github.com/matrix-org/synapse/issues/15633))
- Re-type config paths in `ConfigError`s to be `StrSequence`s instead of `Iterable[str]`s. ([\#15615](https://github.com/matrix-org/synapse/issues/15615))
- Re-type config paths in `ConfigError`s to be `StrSequence`s instead of `Iterable[str]`s. ([\#15615](https://github.com/matrix-org/synapse/issues/15615))
- Update Mutual Rooms (MSC2666) implementation to match new proposal text. ([\#15621](https://github.com/matrix-org/synapse/issues/15621))
- Update Mutual Rooms ([MSC2666](https://github.com/matrix-org/matrix-spec-proposals/pull/2666)) implementation to match new proposal text. ([\#15621](https://github.com/matrix-org/synapse/issues/15621))
- Remove the unstable identifiers from faster joins ([MSC3706](https://github.com/matrix-org/matrix-spec-proposals/pull/3706). ([\#15625](https://github.com/matrix-org/synapse/issues/15625))
- Remove the unstable identifiers from faster joins ([MSC3706](https://github.com/matrix-org/matrix-spec-proposals/pull/3706)). ([\#15625](https://github.com/matrix-org/synapse/issues/15625))
- Fix the olddeps CI. ([\#15626](https://github.com/matrix-org/synapse/issues/15626))
- Fix the olddeps CI. ([\#15626](https://github.com/matrix-org/synapse/issues/15626))
- Remove duplicate timestamp from test logs (`_trial_temp/test.log`). ([\#15636](https://github.com/matrix-org/synapse/issues/15636))
- Remove duplicate timestamp from test logs (`_trial_temp/test.log`). ([\#15636](https://github.com/matrix-org/synapse/issues/15636))
- Fix two memory leaks in `trial` test runs. ([\#15630](https://github.com/matrix-org/synapse/issues/15630))
- Fix two memory leaks in `trial` test runs. ([\#15630](https://github.com/matrix-org/synapse/issues/15630))
