Multi-tenant SaaS billing platform on AWS combining Route 53 DNS, CloudFront CDN, AWS WAF, and ALB for global edge delivery and DDoS protection. Application tier runs ECS Fargate microservices (Billing API, Invoice Renderer) across two availability zones with SQS decoupling, while Stripe webhooks trigger Lambda handlers via API Gateway for real-time payment events. Data layer uses Aurora PostgreSQL with read replicas for high-throughput queries, ElastiCache Redis for session management and rate limiting, and S3 with Glacier archival for invoice storage and compliance. This architecture demonstrates multi-AZ resilience, event-driven processing, and cost-optimized storage tiering essential for production SaaS platforms. Fork and customize this diagram on Diagrams.so to match your tenant isolation strategy, billing workflows, or compliance requirements.