Middleware functions are functions that have access to the request object (req), the response object (res), and the next function in the application’s request-response cycle. The next function is a function in the Express router which, when invoked, executes the middleware succeeding the current middleware.
Securing Node.js RESTful APIs with JSON Web Tokens
Adnan Rahić

Very thorough

Adnan Rahić

Appreciate the thorough walk through and highlighting the middleware approach. This was very successful for our team.