Mobile App Backend

A robust, scalable backend infrastructure designed to power modern mobile applications with millions of users.

Key Features

• RESTful API: Well-documented endpoints following REST best practices
• Authentication & Authorization: JWT-based auth with refresh tokens
• Push Notifications: Multi-platform notifications via FCM and APNs
• File Upload: S3-based file storage with image processing
• Third-party Integrations: Payment processing, analytics, and social login
• Rate Limiting: Protection against abuse and DDoS attacks

Architecture

API Design

• Versioned endpoints for backward compatibility
• Consistent error handling and status codes
• Request validation with comprehensive schemas
• CORS configuration for web client support
• API documentation with OpenAPI/Swagger

Scalability

• Horizontal scaling with load balancers
• Redis caching for frequently accessed data
• Database connection pooling
• Async job processing for heavy operations
• CDN integration for static assets

Security

• Input sanitization to prevent injection attacks
• Rate limiting per user and IP
• HTTPS-only communication
• API key rotation and management
• Security headers (HSTS, CSP, etc.)

Performance Optimizations

• Database Indexing: Optimized queries with proper indexes
• Caching Strategy: Multi-layer caching (Redis, CDN, browser)
• Connection Pooling: Efficient database connection management
• Compression: Gzip compression for API responses
• Pagination: Cursor-based pagination for large datasets

Monitoring & DevOps

• CloudWatch metrics and alarms
• Automated health checks and auto-recovery
• Blue-green deployments for zero downtime
• Comprehensive logging with structured logs
• Error tracking with Sentry

Technologies Used

• Runtime: Node.js 20+
• Framework: Express.js
• Database: PostgreSQL, Redis
• Cloud: AWS (EC2, S3, CloudFront, RDS)
• Auth: JWT, Passport.js
• Notifications: Firebase Cloud Messaging, APNs
• Testing: Jest, Supertest
• CI/CD: GitHub Actions, AWS CodeDeploy