Worked on improving asynchronous context handling in the dotnet/fsharp repository, focusing on the FSharp.Core library. Addressed a bug in Async.SwitchToContext by enabling support for null SynchronizationContext values, which prevents null-reference errors in environments lacking a synchronization context. Enhanced code quality by adding nullability annotations, supporting better static analysis and safer API usage. The work centered on asynchronous programming and library development using F#, with attention to compiler development practices. No new features were introduced during this period, as efforts were directed toward increasing robustness, maintainability, and reliability of asynchronous operations within the FSharp.Core codebase.