Worked on backend reliability improvements for the suitenumerique/drive repository, focusing on WOPI integration with S3 object storage. Addressed a critical issue where missing VersionId fields in S3 responses caused 500 errors during file operations. Implemented a targeted fix by replacing reliance on VersionId with ETag, ensuring more robust handling of edge cases and reducing the risk of incidents. Collaborated with other contributors to deliver this change, which stabilized WOPI behavior and improved file access reliability for end users. Utilized Python for backend development and testing, applying API development skills to enhance the dependability of cloud-based file operations.