Backend Developer for Auth System

We need a backend developer to build the authentication and database layer for our application using Node.js and PostgreSQL. The role involves designing and implementing secure authentication systems and optimizing database schema for performance. The ideal candidate will have experience in Node.js and PostgreSQL, and be able to work independently to deliver high-quality solutions. Scope: — User registration · login · logout · password reset — JWT-based session management — PostgreSQL database with four tables: Users · Sessions · Results (stores up to 50 named numerical values per session) · Purchases (fields: purchase_id · user_id · session_id · stripe_payment_intent_id · status · created_at · pdf_url) — REST API endpoints for auth and CRUD on the above tables — Environment variable management — Basic rate limiting Stack: Node.js · Express · PostgreSQL · JWT Deliverables: — Working auth API with documented endpoints — Database schema with migration files — Postman collection for testing all endpoints — README with setup instructions Small focused scope. Fixed price only. Share your estimate and timeline.