Worked on the netlify/build repository to enhance the reliability and efficiency of Netlify function deployments. Addressed an ESBuild-related issue by implementing deterministic ZIP archiving, ensuring that source files are consistently ordered when creating archives. This approach guarantees byte-identical ZIP files across builds, which prevents unnecessary re-uploads of unchanged functions and improves build cache effectiveness. The solution involved sorting srcFiles before packaging, directly reducing bandwidth usage and deployment times in production environments. Utilized Node.js, TypeScript, and full stack development skills to deliver a targeted bug fix that strengthened build reproducibility and streamlined the function packaging process for Netlify.