Highly Available Three-Tier Web Application
Architect and deploy a production-grade three-tier web application: EC2 Auto Scaling Group behind an Application Load Balancer (web tier), RDS Aurora Multi-AZ with read replicas (database tier), ElastiCache Redis (session/caching tier), S3 + CloudFront for static assets, and Route 53 latency routing across two regions. Implement least-privilege IAM roles throughout.