MERN Backend Update & Bug Fix

I’m looking for someone who can jump straight into an existing MERN stack repo and clean up two critical areas on the server side:

1. API endpoints – several routes are returning incorrect data or failing altogether. I need the logic reviewed, the controllers refactored where necessary, and reliable responses restored.

2. Authentication and authorization – sessions are unstable and access rules are being bypassed in edge cases. Please audit the auth flow, tighten any leaks, and ensure protected routes behave as intended.

The codebase runs on Node.js / Express with MongoDB + Mongoose, and JWT for tokens. You’ll have access to the private GitHub repo and a Postman collection for quick testing. Once your fixes are in, I’ll validate them against the existing unit tests and a short regression checklist; all tests must pass and the endpoints should respond in under 300 ms on my staging server.

If you’ve tamed similar issues before and can deliver clean, well-commented commits, let’s get started right away.