For experienced programmers: A recap is always welcomed.
For beginners: you will have a description of what are and how middlewares work in a Go web app. Don't forget, the comments section is open. Leave a comment if you need more explanations.
We will see what middlewares mean from a web application perspective.
Middleware is a way for defining the separation of concerns in an application (distributed or not). Sometimes is called "the glue" or "plumbing" since it helps "glue" together different services and passes data between them  . Web applications are used for executing a set of instructions before the request is handle by a controller. The instructions are usually to filter the requests (e.g. is this user allowed to access this page?), logging the request and the list can continue.
Requirement: Implement a logging middleware for AWS Lambda.
Checkout this repository.