Lambda and API Gateway in front of Bedrock

Advantages of using API Gateway

• Authentication and Authorization: Integrates well with IAM, Cognito, or custom authorizers to secure access.
• Rate Limiting and Throttling: Protects expensive Bedrock interactions from abuse or accidental overuse.
• Custom Domains: Adds a layer of flexibility for exposing the endpoint publicly.
• Built-in caching to reduce Bedrock calls
• Timeout Increase (Post-April 2024): Default is 29 seconds; but for Regional REST APIs and private REST APIs it can increase beyond 29 seconds, but this might require a reduction in your account-level throttle quota limit.

Advantages of using Lambda

• Add custom logic or preprocessing before sending requests to Bedrock
• Security Boundary: Keeps Bedrock credentials hidden from clients and encapsulates business logic.
• Retries & Error Handling: Can handle transient errors or implement fallbacks/retry logic for Bedrock

Disadvantages of the Topology

• Additional latency due to multiple hops
• No Streaming Support in REST/HTTP API Gateway
• Higher cost per request (API GW + Lambda + Bedrock)
• For infrequent calls, Lambda cold starts may introduce initial latency. Provisioned concurrency can help, but it's an added cost.
• Payload Size Limits: Lambda has limits (~6 MB for sync invocation), so watch out for large prompt/response interactions.

Best Practices around this architecture

• Use provisioned concurrency for Lambda to minimize cold starts
• Consider using WebSocket API if streaming is required
• Use AWS X-Ray for distributed tracing
• Consider implementing a dead-letter queue for failed requests