Worked on Submitty/Submitty and laurent22/joplin, delivering six features and one bug fix focused on security, reliability, and performance. Enhanced CI/CD pipelines by enforcing least-privilege GitHub token permissions and introducing concurrency controls to cancel outdated workflow runs, optimizing resource usage. Improved database efficiency in Submitty by refactoring user queries to eliminate N+1 issues using PHP and batch fetching. Strengthened UI consistency and user experience through synchronized attachment toggles and refined password entry on mobile, leveraging JavaScript and React Native. Added validation for server URL protocols to prevent misconfigurations, ensuring robust workflow management and comprehensive test coverage across both repositories.