Worked on the AvaloniaUI/angle repository to enhance validation coverage in the graphics stack by implementing a targeted test for a known ANGLE validation bug affecting CubeMap rendering. Used C++ and GLSL to develop the CubeMapBug2 test, which reliably reproduces issues related to texture samplers and binding units. To maintain CI stability, configured the test to be skipped in end-to-end expectations while the root cause is investigated, ensuring uninterrupted release cycles. This approach improved test coverage and provided a clear path for future bug diagnosis and fix verification, leveraging skills in graphics programming, shader development, and automated testing workflows.