Worked on the fastify/fastify repository to address a critical memory leak affecting keep-alive connections in high-concurrency environments. Focused on backend development using Node.js and JavaScript, the work involved clearing socket metadata after each response to prevent retention of request and reply objects across requests. This approach included implementing a guard to ensure cleanup occurred only for the correct request, as well as adding regression tests to verify that socket state was properly reset after responses. The changes improved reliability and maintainability of the codebase, reducing memory growth under sustained traffic while maintaining compatibility and documenting the technical solution.