Yaowen Mei worked on optimizing sysgraph generation performance for the google/oss-rebuild repository, focusing on accelerating large-build sysgraph creation and improving reliability. Using Go for backend development, Yaowen implemented a stack-based dependency traversal to replace previous approaches, which reduced sysgraph generation time from over 60 minutes to approximately 6 minutes on large builds such as the android m build. The work also included enhanced error handling to minimize build failures and improve diagnostics. This feature demonstrated a deep understanding of backend performance bottlenecks and effective use of Go to deliver a robust, maintainable solution for complex dependency management challenges.