Worked on stabilizing thumbnail retrieval in the shaka-project/shaka-player repository by addressing a race condition affecting the getAllThumbnails function. The solution involved introducing a debounced timer to manage the closing of the segment index, which prevented premature closure during concurrent requests and improved the reliability of thumbnail loading. This JavaScript-based fix enhanced the user experience by reducing intermittent failures in thumbnail display across different streaming sessions and environments. The work demonstrated a strong focus on front end development and testing, ensuring that the changes were robust and maintainable within the existing codebase while directly improving streaming functionality for end users.