During January 2025, Caisi focused on backend reliability for the 0xJacky/nginx-ui repository, addressing critical issues in WebSocket error handling and user authentication. Working primarily in Go, Caisi resolved a Windows-specific bug to ensure client-closed WebSocket errors were correctly classified, improving the accuracy of analytics logs and disconnection reporting. Additionally, Caisi enhanced the authentication flow by preventing duplicate usernames during registration and refining ban logic to properly initialize tracking for new IP bans and halt further execution after a ban is triggered. This work demonstrated depth in API development, error handling, and robust backend engineering, strengthening overall system reliability.