Worked on the Intermesh/groupoffice repository to enhance the reliability of database maintenance operations by addressing a critical bug in the cleanup script. Focused on improving data integrity, the developer corrected the use of foreign_key_checks by switching from OFF/ON to 0/1 and updated the deletion path from ta_tasklists to tasks_tasklist for cal_visible_tasklists. This SQL scripting work reduced the risk of data loss and ensured more predictable cleanup runs. Demonstrated strong skills in database management, careful script debugging, and disciplined version control, resulting in a traceable and maintainable patch that improved operational stability for ongoing maintenance tasks.