Blog
CloudFront Functions and Lambda@Edge: injecting CORS without warming every PoP
Lightweight edge JS can normalize Access-Control-* on cached objects; Lambda@Edge handles heavier auth transforms.
1 min read
cloudfrontcdncors
Cache keys
Include Origin in the cache key when responses vary by caller origin; otherwise you may serve wrong Allow-Origin.
Document whether OPTIONS is cached or always forwarded to origin.
Cost controls
Prefer CloudFront Functions for sub-millisecond edits at scale.
Monitor Lambda@Edge throttles during traffic spikes and preflight storms.