App Developer Needed for Backend Integration and Implementation

Hi, I have an existing mobile app (React Native) that needs backend integration work done. The frontend is mostly built but it's currently running on dummy/static data. I need an experienced developer to connect everything to a real backend, set up APIs, and make the app fully functional. What needs to be done: Connect the existing React Native frontend to a Node.js/Express backend Set up and integrate RESTful APIs across all app screens Implement user authentication (JWT-based login/register) Connect to a database (MongoDB or PostgreSQL) Integrate third-party services (push notifications, payment gateway, or social login — TBD) Handle error states, loading states, and edge cases properly Test all API endpoints and ensure stable performance Deploy backend to a cloud server (AWS / DigitalOcean / Railway) What I'll provide: Full access to the existing React Native codebase Design files and screen flow documentation List of all API endpoints needed per screen Access to third-party service accounts Budget: $600 Timeline: within a week Note: Only apply if you have real experience integrating backends into mobile apps. Share relevant examples.