Job description Locations: India, Turkey, Azerbaijan - REMOTE We are a fast-growing startup building a gym management and fitness tracking SaaS platform. We are looking for an experienced Backend Developer to scale our existing infrastructure and ship new features. **About the Role** You will take ownership of our backend architecture, work closely with the frontend team on API integration, and help migrate legacy C#/.NET code to a modern Node.js stack. This is a long-term engagement with room to grow as the platform scales. **Core Responsibilities** - Design and build scalable backend architecture using NestJS and TypeScript - Database design and optimization with PostgreSQL + TypeORM / Prisma - Implement RESTful APIs, JWT authentication, CQRS, and Clean Architecture principles - Integrate Firebase Auth and push notifications - Set up and manage MinIO / AWS S3 file storage - Containerization and deployment management using Docker - Collaborate with frontend team on API integration - Migrate legacy C#/.NET codebase to Node.js - Write unit and integration tests; participate in code reviews **Tech Stack** - **Backend:** Node.js, NestJS, TypeScript, TypeORM / Prisma - **Database:** PostgreSQL, Redis - **DevOps:** Docker, Docker Compose, CI/CD (GitHub Actions / GitLab CI) - **Cloud:** Firebase, MinIO / AWS S3 - **Testing:** Jest, Supertest - **Version Control:** Git, GitHub / GitLab **Requirements** - 3+ years of backend development experience - Strong proficiency in NestJS and TypeScript - Solid understanding of RESTful API design and Clean Architecture - Experience with PostgreSQL and ORM tools (TypeORM or Prisma) - Familiarity with Docker and containerized deployments - Fluent written and spoken English (for technical documentation and async communication) **Nice to Have** - Ability to read and understand C#/.NET code - Experience with DDD, Microservices, GraphQL, or Event-driven architecture - Redis caching experience - i18n / multi-language system implementation - Legacy codebase refactoring experience **What We Offer** - Long-term collaboration with a growing startup - Work with modern technologies and best engineering practices - Dynamic and innovative technical team - Performance-based salary growth - Future equity potential **Work Type:** Remote (Anywhere) **Engagement:** Full-time / Part-time / Freelance **Rate:** Negotiable based on experience and portfolio **To Apply, Please Answer:** 1. Share your experience with NestJS and TypeScript — what's the largest system you've built? 2. Have you worked on a C#/.NET to Node.js migration before? If yes, describe the approach. 3. Attach your GitHub profile or relevant portfolio links. Applications without answers will not be reviewed.