A Comprehensive Guide to Lambda@Edge

Lambda@Edge is a feature of AWS (Amazon Web Services) Lambda. It enables you to run code closer to the users of your application, which improves performance and user experience.

Why it's important?
Unlike AWS Lambda, which executes functions in response to events in a single AWS region, Lambda@Edge executes functions in response to events generated by Amazon CloudFront. This leads to reduced latency and better performance as it allows the running of code closer to the users' location.

What is it?
Lambda@Edge is essentially a compute service. You can use it to customize content that CloudFront delivers, executing the code in AWS locations globally closer to the user’s location.

How it works?
- AWS CloudFront triggers a function when it receives a request from a viewer - The code runs in an AWS location close to the viewer - The function returns a response to CloudFront, which is then returned to the viewerLambda@Edge scales automatically, running your code in response to CloudFront events.

Exam Tips: Answering Questions on Lambda@Edge
Understanding : Comprehension of Lambda@Edge and its use cases is important for answering exam questions. Understand when to recommend its use, such as improving user experience by reducing latency.
Applying concepts : Be able to describe how to set up Lambda@Edge and how it integrates with CloudFront in the AWS ecosystem.
Time management : Lambda@Edge questions are generally straightforward, so they shouldn’t need too much of your time.
Practice : The more you practice answering Lambda@Edge questions, the more comfortable and quicker you become during the actual exam.