Julien Cassette developed ZFS reflink support for both the Radarr and Sonarr repositories, extending copy-on-write file transfer capabilities to ZFS volumes. By updating backend C# services to invoke TryCreateRefLink and TryRenameFile during copy and move operations, Julien ensured parity between ZFS and existing Btrfs workflows. This integration improved large-file transfer performance and storage efficiency, reducing I/O load for media libraries. Julien’s work in backend development and system programming focused on cross-filesystem compatibility, laying groundwork for future optimizations. The depth of the implementation addressed both technical consistency and scalability, enhancing the developer experience across Radarr and Sonarr’s file system operations.