Everything You Need to Know About Express.js Middleware

Master Middleware to Build Faster, More Scalable Node.js Apps

Introduction

Let’s be honest: the word “middleware” sounds like something out of a sci-fi movie, maybe a mysterious layer between two planets or the glue that holds the universe together. Well, in the realm of Express.js, it’s not that far off! Middleware is indeed the glue that holds your app’s functionality together, making sure everything runs smoothly, like a well-oiled machine — or at least a well-oiled sandwich assembly line.

But what exactly is middleware? Why do you need it? And, most importantly, how do you use it to level up your Express.js applications? In this guide, we’ll take a deep dive into everything middleware-related. We’ll look at the various types of middleware, how they work, and some best practices to keep your app functioning at top-notch efficiency.

So, let’s get started!

What Exactly Is Middleware?

So, let’s break it down.

Imagine you’re at a five-star restaurant. You don’t just sit down and immediately get served your dish. Nope, first you’re greeted by a host, then shown to your table, you order appetizers, and finally, after much anticipation…