Worked on enhancing conflict resolution in the cozy/cozy-client repository by introducing a FailOnConflict option to the moveToCozy method. This feature allows file operations to fail explicitly with an HTTP 409 status when a conflict is detected, rather than automatically renaming files, thereby improving predictability for client integrations. The implementation aligned the behavior with NextcloudFileCollection, supporting clearer conflict resolution semantics. The work was carried out using JavaScript and full stack development skills, focusing on backend logic and API consistency. This targeted enhancement addressed integration reliability, providing developers with more transparent and controllable file handling during synchronization processes.