Multi-domain three-tier architecture on AWS using Route 53 to distribute traffic across three independent ALBs, each serving a separate domain with dedicated application and database tiers. Application servers (t3.medium) in private subnets across three availability zones connect to database servers (r5.large) and S3 Standard storage for active workloads. GuardDuty, Inspector, AWS Backup, and CloudWatch provide comprehensive security monitoring, compliance scanning, and disaster recovery across all tiers. Fork this diagram to customize domain names, instance types, or add auto-scaling policies for your multi-tenant SaaS or enterprise application. The architecture demonstrates high availability, fault isolation per domain, and defense-in-depth security practices.