AWS 3-tier web application spanning two availability zones with WAF protection, Application Load Balancer, Auto Scaling EC2 instances, and RDS PostgreSQL primary-replica replication. User traffic flows through WAF and ALB to t3.medium EC2 instances across AZ-1 and AZ-2, while static assets are served from S3. Application tier instances in private subnets connect to RDS PostgreSQL primary in AZ-1 and read replica in AZ-2 for database resilience and read scaling. NAT Gateways in public subnets enable outbound connectivity from private application and data subnets. This architecture demonstrates AWS best practices for fault tolerance, auto-scaling, and database high availability across regions. Fork and customize this diagram on Diagrams.so to match your VPC CIDR blocks, instance types, or add additional replicas.