Three-tier web application architecture combining React.js frontend, Node.js Express backend, and PostgreSQL database with Redis caching and high-availability patterns. User and admin traffic flows through WAF and CDN to dual React portals, then through an ALB to a REST API Gateway that routes requests to specialized modules including User Management, Admin Management, Notifications, Find Owners, and Create Events. Each module connects to Express.js business logic, which handles authentication, monitoring, and data persistence to a PostgreSQL primary database with read replicas and Redis cache for performance optimization. This architecture demonstrates separation of concerns, horizontal scalability, and production-ready patterns for modern web applications. Fork and customize this diagram on Diagrams.so to match your specific microservices, add additional modules, or adjust caching strategies for your use case.