This is part 6 of 15 part series on building web server with go. Checkout https://www.gophersumit.com/series/web-server/ for more. middleware Middleware is used to provide a processing pipeline for web servers. Middleware is way of providing shared processing functionality for our web handlers. Whenever there is incoming request to our web server, we may want to log it, check if user is authorized etc. While sending response back to client, we may want to perform compressions, set some custom headers etc.