React Developer Needed to Fix Auth, Admin Panel & Backend Issues on Existing Website

I have a live website built in React (originally scaffolded with Lovable) that's functional but running into some backend and performance issues I need a solid developer to dig into and fix — then help me optimize it going forward. To be upfront: this isn't a "build from scratch" job. The site is already live and has real users, so I need someone who's comfortable working inside an existing codebase, debugging carefully, and not breaking things that already work. Here's what's currently broken: Session persistence in authentication — Users are getting logged out or losing their session unexpectedly. I need someone to identify why sessions aren't persisting properly and implement a reliable fix (token refresh, storage handling, expiry logic — whatever the root cause turns out to be). Admin panel not showing authenticated users — The admin dashboard should display currently authenticated/active users, but it isn't pulling or rendering that data correctly. Admin panel CRUD operations failing — Create, read, update, and delete actions in the admin panel aren't working as expected. This appears to be tied to REST API issues on the backend (could be endpoint bugs, incorrect request handling, permission/auth middleware, or response parsing — I need someone who can actually trace it down rather than guess). On top of the fixes, I also want: A general performance/speed audit and optimization pass on the frontend (React) — things like reducing load times, cutting unnecessary re-renders, optimizing bundle size, lazy loading, etc. Clean, documented changes so I (or future developers) can understand what was changed and why. What I'm looking for in you: Strong hands-on experience with React.js and debugging production React apps Solid backend/REST API troubleshooting skills (Node.js/Express or similar — happy to share the actual stack once we connect) Real experience with authentication systems — specifically session/token persistence issues Comfortable reading and navigating someone else's existing codebase Bonus: experience with apps originally built using Lovable or similar AI-assisted builders, since there can be some quirks in how that code is structured How I'll evaluate proposals: I'm not looking for a copy-paste pitch. In your proposal, briefly tell me: How you'd approach debugging a session persistence issue without seeing the code yet (just your general diagnostic process) A time you fixed a similar "admin panel / CRUD not working" type bug — what was the actual root cause?