Node.js React Developer for Production Code Audit and Enhancement

We have a live production web application built with Node.js, Express, React, and MongoDB, and we're looking for an experienced MERN Stack/Node.js developer to diagnose and resolve a production issue affecting real users. Alongside fixing the bug, we'd also like a lightweight audit of the relevant code to identify any underlying issues that could cause similar problems in the future. This is a hands-on debugging role. We need someone who can quickly understand an unfamiliar codebase, identify the root cause, implement a clean fix, and work independently without constant guidance. What You'll Do - Diagnose the root cause using the bug description, logs, screenshots, and relevant code - Perform a focused audit of the affected area to identify potential bugs, security concerns, performance bottlenecks, or code quality issues - Implement a clean, targeted fix without disrupting existing functionality - Test and verify the solution in our environment before handover - Provide a concise report covering: - The root cause of the issue - What was changed - How the fix was verified - Any additional findings or recommendations from the audit What We're Looking For You should have: - Strong production experience with Node.js and Express - Solid experience with React and MongoDB - The ability to quickly understand and debug unfamiliar codebases - Strong log-driven debugging skills - Previous experience fixing bugs in live production applications - The ability to work independently and move quickly when users are affected This is not a tutorial or greenfield project. We're specifically looking for someone who has dealt with real-world production issues and understands the importance of making focused fixes without introducing new problems. If you're comfortable debugging production Node.js/React applications and can get to the root cause efficiently, we'd like to hear from you.