- Improve performance of incoming federation transactions in large rooms. ([\#9953](https://github.com/matrix-org/synapse/issues/9953), [\#9973](https://github.com/matrix-org/synapse/issues/9973))
- Improve performance of incoming federation transactions in large rooms. ([\#9953](https://github.com/matrix-org/synapse/issues/9953), [\#9973](https://github.com/matrix-org/synapse/issues/9973))
- Rewrite logic around verifying JSON object and fetching server keys to be more performant and use less memory. ([\#10035](https://github.com/matrix-org/synapse/issues/10035))
- Rewrite logic around verifying JSON object and fetching server keys to be more performant and use less memory. ([\#10035](https://github.com/matrix-org/synapse/issues/10035))
- Add an admin API for unprotecting local media from quarantine. Contributed by @dklimpel. ([\#10040](https://github.com/matrix-org/synapse/issues/10040))
- Add an admin API for unprotecting local media from quarantine. Contributed by @dklimpel. ([\#10040](https://github.com/matrix-org/synapse/issues/10040))
- Add new admin APIs to remove media by media ID from quarantine. Contributed by @dkimpel. ([\#10044](https://github.com/matrix-org/synapse/issues/10044))
- Add new admin APIs to remove media by media ID from quarantine. Contributed by @dklimpel. ([\#10044](https://github.com/matrix-org/synapse/issues/10044))
- Make reason and score parameters optional for reporting content. Implements [MSC2414](https://github.com/matrix-org/matrix-doc/pull/2414). Contributed by Callum Brown. ([\#10077](https://github.com/matrix-org/synapse/issues/10077))
- Make reason and score parameters optional for reporting content. Implements [MSC2414](https://github.com/matrix-org/matrix-doc/pull/2414). Contributed by Callum Brown. ([\#10077](https://github.com/matrix-org/synapse/issues/10077))
- Add support for routing more requests to workers. ([\#10084](https://github.com/matrix-org/synapse/issues/10084))
- Add support for routing more requests to workers. ([\#10084](https://github.com/matrix-org/synapse/issues/10084))
- Report OpenTracing spans for database activity. ([\#10113](https://github.com/matrix-org/synapse/issues/10113), [\#10136](https://github.com/matrix-org/synapse/issues/10136), [\#10141](https://github.com/matrix-org/synapse/issues/10141))
- Report OpenTracing spans for database activity. ([\#10113](https://github.com/matrix-org/synapse/issues/10113), [\#10136](https://github.com/matrix-org/synapse/issues/10136), [\#10141](https://github.com/matrix-org/synapse/issues/10141))
