Yuka focused on stabilizing and maintaining critical infrastructure in open source projects over a two-month period. In mongodb-js/mongosh, Yuka addressed an npm package-lock integrity issue by restoring missing integrity fields using external tooling and validating lockfile consistency with npm, which improved build reproducibility and reduced CI risk. Later, in Mic92/nixpkgs, Yuka reverted the matrix-synapse-s3-storage-provider to an earlier version to restore compatibility with matrix-synapse, updating the Nix expression and hash to ensure reproducible deployments. Yuka’s work demonstrated proficiency in package management, system configuration, and languages such as JSON and Nix, focusing on reliability and deployment stability.