Worked on the microsoft/WindowsAppSDK repository to enhance authentication reliability and platform compatibility. Developed comprehensive unit tests for the OAuth2Manager API using C++ and a mock HTTP server, employing in-process interception to simulate various authentication flows, token requests, and error scenarios. This approach ensured robust coverage and reduced integration risk for future development. Additionally, updated the OAuthTestApp and OAuthTestAppPackage to target Windows 10.0 general and 10.0.19041.0, improving compatibility with the latest Windows SDK. Leveraged skills in build systems, Windows API, and unit testing to support smoother CI validation and facilitate partner integrations across the Windows ecosystem.