During December 2025, Jan Kuglics focused on improving input reliability for the zed-industries/zed repository by addressing a critical X11 scroll stability issue. Using Rust and leveraging skills in UI development, event handling, and system programming, Jan implemented a fix that resets the mouse scroll state when the application loses focus. This approach prevents the accumulation of scroll deltas, which previously caused large, unexpected jumps when users returned to Zed after switching to other applications. The solution enhanced user experience during focus transitions, reduced potential frustration, and was thoroughly documented in the release notes, reflecting careful attention to both code and usability.