CloudFront

A client’s site returned intermittent HTTP 503s that were impossible to reproduce. The trail led to a Lambda@Edge origin-response function hitting a 3-second timeout on sequential cross-region calls to DynamoDB in us-east-1 and S3 in eu-west-1 — while executing in Asia Pacific. Here’s how CloudFront’s request path explains it.

When building production-grade enterprise solutions on AWS, we try to follow all the best practices. But what happens when CDK itself creates unexpected issues? A deep dive into a real-world problem with CloudFront caching and CDK configuration.