Building with API Gateway, Lambda and DynamoDB Single-Table Design for Multi-Tenant SaaS

When I build multi-tenant SaaS on AWS, one of my favorite combinations is API Gateway + Lambda + DynamoDB . It gives me a clean serverless control plane, fast iteration, and a lot of flexibility in how I model data and enforce tenancy. In this post, I will walk through an end-to-end implementation pattern for a multi-tenant SaaS API using: Amazon API Gateway for API ingress AWS Lambda for business logic Amazon DynamoDB with a single-table design Amazon Cognito + JWT for authentication Per-tenant throttling and quotas using API Gateway usage plans (with a Lambda authorizer pattern) I will focus on the architectural and data modeling decisions that matter in production: Tenant isolation patterns Partition key design Hot partition mitigation GSIs for access patterns Auth context propagation (Cognito/JWT) Per-tenant throttling and quotas I will also include code and an implementation walkthrough so you can adapt the pattern to your own SaaS. Why this stack works so well for multi-tenant Sa