Backend Engineer - Node.js + Redis + LatAm Payment Integration (Serverless - 1 Month)

Need a Senior Backend & Cloud developer. Frontend (React) is already built and will be provided. BUILD AND INTEGRATE: PostgreSQL database: users, wallets, transactions. Redis: real-time leaderboard with WebSockets/Socket.io. Authentication: email/password, email verification. Multi-room system: 3 independent instances running simultaneusly, each with its own leaderboard, prize pool and entry fee. Auto-detect user country at login and assign to corresponding room. Cron job system: automated 30-minute cycles. Payment processor: automated payouts for gaming/ skill platforms. Must support USA, Mexico and Brazil (Pix). Wallet system: balance, claim, withdrawal, automated payouts. Affiliate system: referral codes, automatic commission tracking and payout. Email notifications: verification, prize won, withdrawal confirmation. API fully connected to provided React frontend. ARCHITECTURE: Elastic/serverless (AWS Lambda or equivalent) with Message Queues (AWS SQS or RabbitMQ). Must scale from 100 to 1,000,000+ concurrent users without bottlenecks. DELIVERABLES: Code on GitHub (access from day 1). Deployed live on AWS. All accounts transferred on delivery.