Backend Developer (iOS & Android) – Health & AI Integration

Requirements
- Proficient in Node.js (NestJS / Express) or Python (FastAPI / Django).
- Strong understanding of API design, data modeling, and authentication (JWT / OAuth2).
- Experience with PostgreSQL or MongoDB.
- Familiar with cloud services (AWS, GCP, or Firebase).
- Knowledge of AI API integration (OpenAI GPT or Google Gemini).

Responsibilities
- Design, build, and maintain scalable RESTful and/or GraphQL APIs for mobile client.
- Integrate AI models (GPT / Gemini) to handle conversational logic, personalized recommendations, and progress tracking.
- Develop and maintain database schemas for users, workouts, nutrition, and progress tracking.
- Implement authentication, authorization, and secure data management practices.
- Handle subscription and payment systems (Stripe / RevenueCat integration).
- Build background jobs for notifications, workout scheduling, and progress insights.
- Collaborate closely with frontend (mobile) engineers and AI engineers to ensure seamless integration.
- Deploy, monitor, and maintain backend services in a cloud environment (AWS / GCP).