Worked on the mozilla/gecko-dev repository to enhance the reliability of Web Platform Tests by addressing issues in session and cookie management. Focused on fixing missed references to the addCookieAndSessionCleanup function, ensuring that test cleanup logic was refactored for greater maintainability without altering core test behavior. Utilized skills in Web Platform Testing and HTML to validate that the updated cleanup processes integrated smoothly with the existing test suite, resulting in no regressions. The work emphasized careful code review and incremental improvement, targeting a single bug fix that improved the stability and maintainability of automated browser testing workflows.