How we 10x Our Lambda@Edge Development Speed 🚀


AWS FOR THE REAL WORLD
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Reading time: 10 minutes
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Main Learning: Building and testing Lambda@Edge functions with CloudFront is complicated, as deployments can take up to 10 minutes. With LocalStack, you can build, test, and debug your Lambda@Edge functions locally!
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Hey Reader 👋🏽

Happy new year! We hope you had a great time with your families and loved ones 😊

We took some time off. Sandro is bridging the cold winter in Thailand (say hi if you're here!) and Tobi started working with a new client project this year. Finally, some HUGE AWS scale again - hopefully we can talk more about that in the future 👀

We don't have any AWS news for you this time. Nothing exciting came out - if you've found something, share it with us!

In this issue, we talk about CloudFront and Lambda@Edge deployments.

Rather watch a video? We've recorded one for you!

Lambda@Edge functions are great for things like:

  • Request forwarding
  • URL rewriting
  • A/B testing

In theory they're powerful. But building and debugging them is a pain. This is what this deep dive is about 👆🏽

video preview

Note: This issue is not sponsored by LocalStack. But we love the tool + the founders. Here's how we've used it for this use case.

Let's get into it!

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📚 This Week's Deep Dive

The Problem: 10-Minute Deployments for Every Change

Lambda@Edge functions are powerful. But debugging them is painful. Even in 2025.

Every change triggers a CloudFront deployment. That's up to 10 minutes of waiting. One typo? Another 10 minutes. Wrong header name? Another 10 minutes.

The Solution: LocalStack for Lambda@Edge

LocalStack lets you run CloudFront and Lambda@Edge locally. Change your function, redeploy in seconds. No waiting. No risk of breaking production.

The video walks through the full setup: LocalStack CLI, creating distributions via awslocal, attaching Lambda@Edge functions, and iterating on custom response headers.

🎬 Watch the Full Tutorial →

Prefer reading? Read the blog post instead

Have you used Lambda@Edge or CloudFront Functions before? If you need more information about CloudFront, here's our infographic!

Our topics for the next weeks:

  • Generating diagrams with Kiro & AI
  • How to save Lambda costs

All of them will come with videos as well!

Have a great start of the year and see you soon!

Sandro & Tobi

PS: Here's a snapshot from Thailand 😊

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