Senior Backend / Full Stack Developer (Node.js + AWS) needed for high-traffic digital product platform

I’m building a scalable web app (PWA) that includes:

- Stripe payment integration (webhooks)
- Automatic generation of unique codes after purchase
- User access system (token-based)
- Audio streaming (audiobook)
- Secure PDF delivery (premium only)
- Album streaming (premium only)
- Raffle system with user codes

Requirements:

- Strong experience with Node.js (Express or NestJS)
- Experience with Stripe webhooks (checkout.session.completed)
- Experience building scalable systems (10k+ concurrent users)
- Knowledge of queues / async processing (SQS, Redis, RabbitMQ)
- PostgreSQL database design
- AWS experience (S3, EC2 or Lambda)
- Ability to build secure access control (token / signed URLs)

Nice to have:
- Experience with PWA (Next.js)
- Experience with media streaming
- Experience with high-load systems

Important:
This system must be built for high traffic. No synchronous webhook processing. Must use async architecture.

Timeline:
MVP required in 3–5 days.