Josh Mock contributed to two open source projects over a two-month period, focusing on system design and build tooling. In elastic/mcp-server-elasticsearch, he modernized package management by removing Yarn and its lockfile, streamlining dependency handling and improving build reliability using JavaScript and YAML. This change reduced maintenance overhead and simplified onboarding for new contributors. In nodejs/undici, Josh enhanced the Agent constructor by introducing a maxOrigins option, allowing developers to cap concurrent origin connections and prevent resource overuse. Implemented in Node.js, this feature preserved backward compatibility while improving error handling and resource management, reflecting thoughtful, targeted engineering within each codebase.