Worked on the open-webui/open-webui repository to deliver an access control performance enhancement focused on backend efficiency. Addressed the challenge of slow permission checks by pre-fetching user group IDs before iterating through models, which reduced the number of database queries required during authorization. This approach lowered database load and improved response times, supporting better scalability for environments with high user concurrency. The solution was implemented using Python and leveraged ORM optimization techniques, including query prefetching and performance tuning. Throughout the process, maintained clear commit traceability, demonstrating a methodical approach to backend development and database optimization within a production codebase.