During October 2025, Sergio Marcelo contributed to the katexochen/nixpkgs repository by delivering patch-level dependency updates focused on improving security and build stability. He updated etcd from version 3.4.37 to 3.4.38 and FluxCD from 2.7.2 to 2.7.3, ensuring the latest patches and security fixes were applied. Sergio refreshed source and vendor manifest hashes to maintain reproducible builds, a critical aspect of reliable package management. His work emphasized traceability, with explicit commits supporting auditability and rollback. Leveraging his expertise in Nix, build systems, and package management, Sergio addressed dependency maintenance with a methodical and reproducibility-focused engineering approach.