Worked on the NixOS/nixpkgs repository to address build system compatibility issues by implementing CMake 4 support for the arrow-cpp and ceph packages. Focused on build system management and package management, the work involved applying targeted patches and updating cpp_redis to ensure seamless integration with the newer CMake toolchain. These changes stabilized builds for downstream users and reduced future maintenance overhead. The approach emphasized maintaining build integrity and coordinating patches across related components, with all modifications documented and linked to relevant issues for traceability. The work was carried out using Nix and centered on robust build systems and package management practices.