Yiyan Tay enhanced user experience and reliability across the martinvonz/jj and ghostty-org/ghostty repositories during March 2026. For martinvonz/jj, Yiyan authored comprehensive documentation for LightJJ, a keyboard-driven browser UI for Jujutsu, focusing on accessibility and onboarding. In ghostty-org/ghostty, Yiyan addressed a keyboard focus issue by implementing a delegate callback to restore terminal input after tab title edits, improving workflow continuity for keyboard-centric users. The work demonstrated proficiency in Swift, UI/UX design, and AppKit focus management, with clear, maintainable commits that emphasized robust user experience and collaboration. The contributions reflected thoughtful, targeted engineering within a short timeframe.