Worked on the jupyterlab/jupyterlab repository to enhance stability and user experience by addressing a specific issue with WebSocket reconnections during kernel and terminal shutdowns. Focused on optimizing the WebSocket close handling logic in TypeScript, the developer updated the shutdown process to recognize normal closure codes and prevent unnecessary reconnect attempts. This involved modifying the _onWSClose function to accept CloseEvent objects and adding checks for standard closure codes, ensuring that normal shutdowns no longer triggered disruptive "Reconnecting..." loops. The work demonstrated strong skills in TypeScript development, testing, and WebSocket handling, resulting in smoother and more predictable application behavior.