During January 2025, Dayeung focused on stabilizing the web-platform-tests/wpt repository by addressing test suite reliability issues. Using JavaScript and Python, Dayeung reverted a recent change that had introduced tests for the Sec-Browsing-Topics image header, which had caused instability and increased maintenance overhead. This work involved carefully removing related test files and utility scripts tied to image loading and header validation, restoring the suite to a more predictable and maintainable state. By isolating the rollback and updating documentation, Dayeung improved test reliability across browsers and environments, demonstrating disciplined change management and a strong emphasis on code quality and maintainability.