During February 2025, Nicolas Lacombe enhanced the file upload experience for the C4illin/ConvertX repository by developing a modernized upload flow using JavaScript and AJAX. He implemented a progress bar with per-file progress tracking and refactored the upload logic to handle files independently, reducing user wait times and improving reliability. Centralized error handling and comprehensive error logging were introduced to streamline debugging and maintenance. By focusing on front end development and robust file handling, Nicolas laid the groundwork for future parallel uploads and scalability. The work demonstrated thoughtful engineering depth, addressing both user experience and maintainability within a single feature release.