Worked on the xapi-project/xen-api repository to enhance upgrade reliability and compatibility in backend systems. Developed group upgrades support for the Yum package manager, enabling upgrades to be triggered even when new packages are not dependencies, thereby addressing dnf5 limitations and improving package management flexibility. Fixed bundle URL construction by adjusting the host parameter in Uri.make, ensuring proper file URL generation for DNF compatibility and reducing upgrade failures. Utilized OCaml for backend development, focusing on robust package management and comprehensive testing. The work demonstrated a methodical approach to resolving cross-environment issues and refining upgrade decision logic within complex infrastructure.