NestJS vs Express.js: Which is the best framework for server-side app development?

From time to time, most developers, when starting a new project, will consider new technologies and re-evaluate existing workhorses. And this is where the NestJS vs Express question arises. But first a little context.

Node.js has grown from an interesting way of taking the V8 engine from the Chrome browser to one of the leading technologies on the market. It allowed JavaScript to transcend its original role as a front-end scripting language into a fully useful all-purpose programming language.

Many developers (myself included) take advantage of the ability to use the same language for front-end and back-end development. Not only is it more comfortable, but it also makes communication between team members easier. If my backend used Laravel or Django as a framework, then I would have to read PHP or Python respectively to understand what the code was doing.

Now, don't take this as an endorsement of there being a single programming language to rule them all. I will be the first to admit that JavaScript, of all the options on the market, is the least suited for this position. That said, it's nice to have the option of a simple, readable language as the basis for your backend.

Node.js as a backend solution is practically synonymous with Express.js, so much so that people consider it the de facto standard server framework for Node.js. But it's not the only option out there, and NestJS is a strong candidate that aims to fill a similar role in the JavaScript ecosystem.

What is a framework?

Before we delve into the details, it's important to understand what is being compared. Both NestJS and Express.js are frameworks, specifically for building backend web applications.

A framework is an opinionated set of tools that serves as a foundation or starting point for creating something. In formal terms: a software framework is an abstraction that provides generic functionality. It can be selectively changed by user-written code, thus providing application-specific software.

In other words, it serves as a generic solution that can be customized by the developer. The goal is to speed up development time by providing basic tools that would otherwise take a long time to install and run. Think of it this way: starting from scratch is like drawing a painting on an empty canvas, and using a frame is like creating the painting from a sketch.

Expresso.js

What are the implications of being a top dog in the market? Express.js is huge in terms of community. Finding useful tutorials, assistance and tricks is very easy, but its biggest advantage by far is the huge number of plugins ready to enhance Express.js.

See, Express is what we call a lightweight, unopinionated framework . That means, straight out of the box, it's as basic as it gets, offering very little in the way of functionality. Starting from scratch will be more work, as many basic things need to be built from scratch.

In return, the developer has more freedom; Returning to our sketch metaphor, you can be more creative when you don't have to paint within the lines.

Fortunately, if you prefer speed over flexibility, plugins exist to streamline the process, so in some ways, if you want the flexibility of a minimalist framework with the option to incorporate more robust solutions, then Express.js development services and framework is for you.

That said, it's not all sunshine and rainbows. Different plugins can be incompatible with each other, so there is an extra step to try to figure out if a set of plugins will work well with each other or if you will need to debug.

NestJS

In many ways, NestJS is the opposite of Express. It’s an extremely opinionated framework that follows the “convention over configuration” design paradigm. In other words, we sacrifice flexibility in favor of standardization and speed. NestJS is based on Angular, so as you'd expect, it's made to be used with TypeScript. (You can still write in Javascript if you prefer.)

TypeScript is a superset of Javascript created by Microsoft, intended to be used as a strictly typed alternative to Javascript that seeks to address some of the common complaints about the language. When used correctly, it helps you write error-free code without losing the simplicity and readability of regular Javascript.

NestJs forces the MVC architecture on the developer, which separates an application into three main logical components: the model, the view, and the controller . It is one of the most popular architectures on the market and NestJs offers a multitude of functions for each component.

NestJS vs Express.js: pros and cons

Both frameworks are strong contenders for small projects; It would be a disservice to any product to point out a winner. That being said, there are a few things to keep in mind.

NestJS is the foolproof solution. If you're a developer looking to dive into the backend for the first time, or your team is just starting out, having the safeguards of an opinionated framework is a welcome feature. With NestJS, you will learn about one of the most popular architectures in web development and also learn the basics of the extremely popular Angular. That's killing two birds with one stone.

That being said, NestJS is also fantastic for a professional. If the project you are going to work on fits within the NestJS framework, you will save dozens of hours of development.

On the other hand, there is a reason why Express.js is so popular. The amount of flexibility is hard to match and is perfect for teams that want to experiment or experiment with non-standard solutions. Lightweight frameworks like Express.js encourage creativity and are perfect for projects that require innovative thinking.

In terms of performance, both are equally capable, and as for scalability, while NestJS is a little easier to scale, Express can offer the same, if not more, with a little work.

NestJS is like one of those Lego Death Star models: if you want to build a Death Star, then it's the perfect solution for you. On the other hand, if you want to build a custom vehicle, you'll be better served by a generic Lego set, and that's what Express.js is for.