Backend Development for Social Networking App

I need an experienced backend developer to build and integrate the backend for a new mobile chat & social app. The frontend is already designed in Figma and implemented in Flutter (iOS & Android).

Backend & APIs:
• Language & Framework: Node.js (NestJS or Express)
• Real-Time Messaging: WebSockets (Socket.io or native ws)
• Authentication: Firebase Auth (Google, Apple, Facebook, Phone OTP)
• Encryption: End-to-end chat encryption using standard libraries (e.g., libsignal)

Database & Storage:
• Primary Database: PostgreSQL (Amazon RDS)
• Cache / Presence / Rate Limiting: Redis (Amazon ElastiCache)
• Media Storage: Amazon S3 with presigned URLs
• Content Delivery: Amazon CloudFront (for images/voice delivery)

Cloud & Infrastructure:
• Hosting: AWS (ECS Fargate or EC2 for backend services)
• Serverless Tasks: AWS Lambda (for background jobs, translations, moderation)
• Messaging Queue: Amazon SQS (for moderation/report workflows)
• Secrets & Config: AWS Secrets Manager

Third-Party Integrations:
• Translation API: Google Translate or DeepL
• Push Notifications: Firebase Cloud Messaging (Android) & Apple Push Notification Service (iOS)
• In-App Purchases: Google Play Billing & Apple In-App Purchase
• Ads: Google AdMob or Meta Audience Network

Admin Panel (Web):
• Framework: Next.js or React
• Purpose: Manage users, view reports, handle unblock requests, monitor analytics

Analytics & Monitoring:
• Analytics: BigQuery export or ClickHouse (for DAU/retention tracking)
• Monitoring: AWS CloudWatch, Sentry (error tracking), Grafana (optional dashboards)

Plus, deployment on PlayStore & AppStore