Worked on the microsoft/kiota repository to enhance the C# code generator by introducing explicit nullable support for primitive types such as integers and booleans, ensuring that generated code correctly handles union wrappers with nullable primitives. Addressed a .NET compilation issue related to unions containing these types, updating both the codebase and documentation to reflect the fix. Expanded unit test coverage to validate the new nullable handling, reducing the risk of future regressions. The work involved C# development, code generation, and thorough testing, resulting in more reliable API client generation and improved developer experience for those integrating with .NET unions.