Worked on the metabrainz/listenbrainz-server repository to deliver two feature enhancements focused on accessibility and user experience. Improved playback controls by adding ARIA labels to icon-only buttons, making them accessible to screen readers and enhancing usability for visually impaired users. Addressed error handling by implementing toast notifications for 'user not found' scenarios, ensuring unique toast IDs to prevent duplicate messages and provide clearer feedback. Updated test coverage to reflect these changes, reducing the risk of regressions and aligning tests with new behaviors. Utilized React, JavaScript, and TypeScript throughout the process, emphasizing front end development, accessibility, and robust testing practices.