Worked on the dotnet/aspnetcore repository to enhance the stability and reliability of HTTP/2 frame writing in ASP.NET Core. Addressed a critical edge case in the Http2FrameWriter by ensuring that negative window sizes are handled gracefully, resetting negative byte counts to zero to prevent out-of-range errors and ensuring the system waits appropriately for window updates. Added a dedicated regression test to lock in this behavior and safeguard against future regressions. This work, implemented in C# with a focus on backend development, networking, and testing, contributed to a more robust HTTP/2 stack under high-load production scenarios.