Worked on the percona/percona-server repository to maintain stability across legacy branches by backporting a critical bug fix from the trunk to Percona XtraDB Cluster versions 8.0 and 8.4. Focused on minimizing regression risk for enterprise deployments, the work involved applying a targeted patch and refining test infrastructure by renaming a variable in a test include file for improved clarity and maintainability. Leveraged skills in SQL, backporting, and testing to ensure the fix was traceable and well-documented. The approach prioritized reliability for customers on older releases, emphasizing careful change management and clear documentation within the codebase.