Worked on enhancing subtitle handling in the jellyfin/jellyfin-vue repository, focusing on improving playback reliability and maintainability. Delivered a targeted refactor that transitioned subtitle stream indexing from MediaStream indexes to TextTrack indexes, enabling more accurate identification and management of subtitle streams across different players. This architectural change reduced the risk of subtitle misidentification and established a foundation for future improvements in subtitle features. Utilized JavaScript, TypeScript, and Vue.js to implement these changes, emphasizing code quality and maintainability. Documented awareness of a known external subtitles bug to support cross-team debugging and risk tracking, while prioritizing long-term architectural improvements over immediate bug fixes.