Multi-AZ three-tier web application on AWS with Route 53 DNS, CloudFront CDN, WAF protection, and Application Load Balancers distributing traffic across Auto Scaling EC2 instances in separate availability zones. Traffic flows from users through Route 53 to CloudFront, then through WAF to ALBs in AZ-1 and AZ-2, which route requests to t3.medium EC2 instances in private subnets. Application tier instances connect to RDS Primary in AZ-1 and RDS Standby in AZ-2 for read replicas and failover resilience. This architecture demonstrates AWS best practices for fault tolerance, auto-scaling, and defense-in-depth security across multiple availability zones. Fork this diagram on Diagrams.so to customize subnet ranges, instance types, or add additional services like ElastiCache or SNS. The multi-AZ design with RDS replication ensures zero-downtime failover and meets enterprise SLA requirements.