Worked on the xapi-project/xen-api repository to deliver VDI revert functionality, enabling virtual machine disk images to be reverted to previous states. Developed new revert_to and revert_from operations in OCaml, incorporating robust validation logic to enforce constraints such as handling live versus snapshot VDIs and clone-backed requirements. Enhanced backend reliability by updating operation validation and introducing comprehensive unit tests to cover both allowed and disallowed revert scenarios, including edge cases like attached snapshots and leaf VDIs. This work improved the maintainability and safety of VM revert workflows, leveraging skills in API design, backend development, and unit testing throughout the process.