AWS – CloudFront Functions

• Lightweight JavaScript functions executed at CloudFront edge locations.

• Optimized for high scale and low latency workloads, with sub-millisecond startup times and support for millions of requests per second.

Typical Use Cases

• Viewer Request: modify or inspect requests after they arrive at CloudFront but before hitting the origin.

• Viewer Response: alter responses before they are sent back to the client.

Architecture Notes

• Built directly into CloudFront (no separate AWS service needed).

• Ideal for simple, short-duration logic.

• Deployed globally with CloudFront distributions.

Lifecycle Events Supported

• Viewer Request

• Viewer Response

• (For Origin Request and Origin Response, use Lambda@Edge instead)