ExpenseFlow demonstrates a production-grade AWS architecture combining CloudFront CDN, API Gateway, and ECS Fargate microservices across isolated VPC subnets. Users authenticate via Cognito JWT, route through Route 53 DNS and WAF-protected CloudFront, then access React SPA and APIs in the distribution layer. Core compute runs Node.js and FastAPI services in private subnets, with messaging via SNS/SQS, data persistence in RDS PostgreSQL with pgvector and Redis caching, and security enforced through Secrets Manager and KMS. Infrastructure is provisioned via Terraform IaC and deployed through GitHub Actions CI/CD, enabling repeatable, auditable deployments. Fork this diagram to customize for your expense management, document processing, or AI-assisted case handling workflows.