This article describes how SeatGeek implemented a serverless architecture for centralized authentication, authorization, and rate-limiting in their multi-tenant SaaS ticketing platform.

• SeatGeek integrated Auth0 with API Gateway and Lambda authorizers for standardized API authentication
• Created tiered usage plans (bronze, silver, gold) with per-tenant rate limits to prevent noisy neighbor problems
• Used DynamoDB to map Auth0 tenant IDs to API Gateway keys for transparent key management
• Implemented multi-level caching: Lambda caches token validation keys; API Gateway caches authorizer responses
• Automated tenant onboarding workflow provisions Auth0 IDs, API keys, and DynamoDB associations via Terraform
• Fully serverless approach eliminates infrastructure management overhead and enables automatic scaling

SeatGeek's solution demonstrates how AWS serverless services can implement secure multi-tenant isolation with centralized access control and cost-efficient resource management.