Mobile App Backend/API Fixes

My existing mobile app is already live, but several critical pieces on the server side are holding it back. I need a developer who can dive straight into the current codebase, resolve the broken backend functionality, and extend the app with new API endpoints... (Budget: ₹1500 - ₹12500 INR, Jobs: Android, Android App Development, API Development, API Integration, Backend Development, Debugging, Mobile App Development, Node.js, React Native)