Three-tier web application architecture on AWS spans two availability zones (us-east-1a, us-east-1b) with CloudFront CDN, WAF, and Route 53 handling global traffic distribution and security. Application Load Balancer distributes requests across EC2 t3.medium instances in private subnets managed by Auto Scaling Groups, while RDS PostgreSQL primary and read replica in separate AZs provide high-availability data persistence. Static assets serve from S3 through CloudFront, NAT Gateways enable outbound internet access from private subnets, and the multi-AZ design ensures fault tolerance and horizontal scalability. This architecture demonstrates AWS best practices for production web applications requiring high availability, automatic scaling, and separation of concerns across presentation, application, and data tiers. Fork this diagram on Diagrams.so to customize VPC CIDR blocks, adjust instance types, add ElastiCache layers, or export as .drawio for team collaboration.