Worked on the sst/opentui repository to enhance editing reliability for CJK (Chinese, Japanese, Korean) text by implementing width-aware extmark positioning. This feature addressed the challenge of accurately placing cursors and marks when editing multi-width characters, reducing drift and improving the overall user experience for CJK input. The solution involved updating extmark adjustments to use visual width calculations, leveraging TypeScript for front end development and integrating Lua-based logic for precise handling. Collaboration with peers and thorough code review ensured a robust implementation, resulting in more stable cursor behavior and improved reliability for users editing CJK content in the application.