Worked on the element-hq/synapse repository to stabilize the MSC3266 feature by delivering a production-ready room summary API endpoint. Focused on backend and API development using Python, the work involved removing the experimental feature flag and introducing a stable /_matrix/client/v1/room_summary/ endpoint while maintaining backward compatibility for existing clients. This approach ensured a seamless migration path and reduced integration complexity for downstream applications. The changes enhanced API reliability and usability, allowing client applications to depend on a well-documented, stable interface. The project concluded with a clean handoff to version 1.15, supporting ongoing maintainability and reducing support overhead.