Worked on BrightspaceUI/labs to deliver two key UI features focused on responsive design and mobile usability. Enhanced the TreeFilter and TreeSelector components by refining resize handling, optimizing dropdown sizing, and removing redundant logic to improve performance and maintainability. Addressed mobile accessibility by adjusting OU filter dropdown widths for better responsiveness. Applied JavaScript, LitElement, and MobX to implement these improvements, emphasizing clean, maintainable code through linting and code cleanup. The work resulted in faster, more reliable dropdown interactions and a more accessible user experience, demonstrating a methodical approach to frontend component design and incremental quality enhancements in a modern web stack.