Technology that scales effortlessly always fascinates me. When a small thing has an effect that can be enormously large.

Signed URLs are the perfect example of this behavior. A function call that runs so fast it is hard to even measure can trigger the movement of gigabytes in other parts of the system.

But signed URLs are interesting not just because of this, but also as the technique is essential for serverless architectures. The Function-as-a-Service model, which is the basis for most serverless solutions, requires a novel way for uploading and downloading files compared to more traditional architectures. The solution is signed URLs.

The concept is not cloud-dependent. There are many subtle differences in how each major cloud vendor offers this functionality, but the main idea is the same. I focus on AWS, and in that case, it’s offered by S3.

What you’ll learn

From this course, you’ll learn how signed URLs are used to allow users to securely download files in a serverless application. You’ll also learn how this architecture is different from traditional, also called 3-tier, architectures and why existing solutions are not usable in that case.

After covering the general concepts, we’ll look into which services work together in AWS to make signed URLs work and how to configure each of them to make sure the solution is both secure and robust.

Finally, you’ll get code samples on how the backend and the frontend are implemented for a file download solution based on signed URLs.

After the course, you’ll have a good understanding of:

  • why signed URLs exist in the first place and why they are required for serverless applications
  • what signed URLs are and what services are needed on AWS for them
  • how to use them in a secure way


This is an email course with 8 lessons each covering a different part of the subject. To not overwhelm your mailbox, you’ll receive a new mail every other day, just to make sure you have the time to follow along.

Theory and practice are both covered. Starting from a bird-eye view, we’ll go into the nitty-gritty of implementation.


It’s free.

Yeah, really. I’m in the process of writing a more in-depth ebook on signed URLs, and I made this email course to cover the basics.


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