Node.js is an open-source Javascript runtime environment and library for executing and running web applications outside a client's browser. It's based on V8, an engine developed by the Chromium Project for web browsers like Google Chrome and Edge.

Consider a scenario where a user interacts with a web application: he only interacts with the application's front-end, but there's a lot of work that goes behind the scenes.

Now, you know that there's a front-end, a server, and a database in a web application. The front-end is developed using Javascript and frameworks like Angular and React JS, while the server is built on Java, PHP, or Node.js, and the back-end database that stores the data usually consists of MySQL or MongoDB.

Let’s take a closer look at what Node.js is, what it is used for, and how it can be a possible solution and support for your web development project.

Table of Contents

What is Node.js used for?
Features of Node.js
Is Node.js used for front-end or back-end?
    ➤  Front-end application
    ➤  Back-end application
    ➤  Main benefits of using Node.js on both ends
Popular apps built with Node.js
Why should you use Node.js?
When should you not use Node.js?

What is Node.js used for?

Node.js is used to develop and run io-intensive web applications like video streaming sites, single-page applications, or online chatting apps. It is the perfect environment for data-intensive applications as it uses a single-threaded, asynchronous event-driven model. This begins to touch down on the advantages of developing within the JavaScript runtime ecossystem, but let's dig deeper into questions like what is Node.js used for, where is Node.js used, and its applications and features.

Features of Node.js

The following are some of the key characteristics that make Node.js the top option among software architects:

  • Productivity: As already mentioned, since Node.js is based on JS, we can use the same language for both front-end and back-end. This increases the productivity of an application buildout.
  • Fast code execution: As Node.js runs on Google’s V8 JavaScript engine, it is very fast in code execution.
  • Asynchronous: Being an event-driven environment, Node.js is able to handle a large amount of requests in a short period of time.
  • Cross-platform compatibility and scalability: NodeJS works on a variety of platforms, including Windows, Unix, Linux, Mac OS X, and mobile devices. It can be used with the appropriate package to create an executable that is 100% self-reliant.
  • Packages: There’s an array of open source Node.js packages in the NPM ecosystem that can simplify developers' work.

Is Node.js used for front-end or back-end?

A common misunderstanding is in regards to where Node.js is used. Many believe that Node.js is primarily used for back-end frameworks and for developing servers, but this is not true: Node.js can be used on both the front-end and the back-end.

The event-driven, non-blocking nature of Node.js frameworks is what makes it a popular choice amongst developers. Because of its adaptive evolution and minimal resource requirements, Node.js has become a standard for business giants like eBay, Uber, and Microsoft.

It's important to note that Node.js is part of popular MEAN and MERN Javascript-centered technology stacks that cover the entire web development pipeline.

Learn more about the MEAN and MERN within JavaScript's ecosystem here.

Let's take a look at how Node.js works and is applied for both front-end and back-end:

Front-end application

  • Module bundlers: A module bundler is a tool that takes pieces of code files and bundles them into a single file for a smoother execution of our applications. Examples of bundlers: Webpack, Rollup, and Browserify.

  • Code linters: A linter is a program that helps identify and correct issues in the codebase. They can detect syntax issues, special standards defined by the development team, and programming faults - the so-called code smells. Custom linters improve the overall efficiency of a company's development staff. One example is ESLint, built with Node.js.

  • Packages: A package contains all the files needed for a module. npm, for instance, provides packages galore to aid in the app programming process. We can access components like text editors, color pickers, authentication components, and so on. Building the front-end is as straightforward as gathering all of the necessary components and sewing them together to create a seamless and appealing user interface.

  • Styling: Styling of web pages is usually done with CSS. Packages such as Bootstrap or style-components have made styling very easy. The latter, for instance, is a library written for React.js, which allows easier integration with JavaScript, and therefore leading to a more efficient styling code for user interaction.

Back-end application

  • Database integration: Node.js has libraries and interfaces that enable smooth database integration. Database integrations allow us to conduct database operations using JavaScript, making the database learning curve much easier to understand.
  • Real-time applications: Applications where performance and scalability are high priority, Node.js helps with its event-driven features and non-blocking I/O. Examples of real-life applications can be software solutions such as live streaming, real-time logistics, tracking, social networking platforms, or hardware solutions such as Internet of Things (IoT).
  • Network and API call: When Node.js sends a data request to the API, it is not halted until the data is received. Instead, after accessing an API, it will go to the next one, and a notification mechanism from a Node.js event will react to the server for the previous API request. In simpler terms, these capabilities allow you to continue working while the request is being processed. Examples: Emails or online forums.

Read also:

Main benefits of using Node.js on both ends

All in all, the application of Node.js on both ends has many benefits.

  • Efficiency and productivity - Thanks to a reduction in context-switching between multiple languages, developers can save a lot of time. Because many technologies are shared between the backend and frontend, using JavaScript for both leads in greater efficiency.
  • Reusability - JavaScript is, as already known, is used to write both backend and frontend with the help of frameworks like Express.js and Meteor.js. Some stacks like MERN, for example, use Express.js as a backend; here, multiple components can be reused between frontend and backend.
  • Building a community - The pace of a successful development cycle is influenced by a thriving online community. When you are stuck on a problem, chances are someone has previously solved it and posted the solution on Stack Overflow. Node.js makes extensive use of this dynamic and highly-engaged community when it comes to the popular runtime and its packages.
Learn how to build Scalable Web Applications with Node.js

Popular apps built with Node.js


Uber chose Node.js to create its large matching system because of its ability to keep up with the pace of Uber's massive business demands and better data processing capabilities. It has benefited the company in many ways:

  • It quickly processes a large amount of data;
  • Programs are reviewed and faults are corrected on the go without having to restart, allowing developers to publish and deploy new code continuously;
  • There’s an open source community which is constantly improving the technology, so it effectively improves on its own.


Node.js was originally used by the world's most popular video streaming service to provide high-volume online streaming for its millions of users. In this early architecture, Netflix sought to provide observability (metrics), debuggability (diagnostic tools), and availability (service registration). The resulting architecture was known as NodeQuark.

NodeQuark basically authenticates and directs requests to an application gateway, which then communicates with APIs and prepares replies before returning them to the client. Netflix has partnered with NodeQuark to create a managed solution that allows teams to create unique API experiences for certain devices, enabling the Netflix app to function on a range of devices.


LinkedIn switched from their synchronous Ruby on Rails mobile app to a Node.js system, as the former required clients to make many requests for a single page. As a result of its scalability, Node.js brought significant performance improvements to the platform:

  • Increased traffic capacity;
  • Improved performance and lowered memory overhead;
  • The mobile app is now up to 20x faster in some scenarios;
  • There is enough headroom to handle 10x current levels of resource utilization.


The primary problem PayPal's engineering team was facing was having to write the frontend and backend with different languages.

Using Node.js helped their developers overcome the barrier between the browser and the server by allowing both browser and server apps to be developed in JavaScript. It merged all engineering skills into a single team, enabling for a better understanding of and response to consumer demands.

Looking for web developers to build your software, website or app with Node.js? We can help you with our dedicated team of developers.

Why should you use Node.js?

Besides the above mentioned reasons, Node.js has a lot of other advantages such as:

  • Having a strong community and bug tracking team.
  • It can be used to build a wide range of apps from Single Page Applications (SPA) like portfolios, streaming apps, ecommerce apps to APIs and online payment systems like Paypal.
  • Hosting Node.js code is not a hassle due to many of its supported hosting platforms.
  • It is lightweight.
  • It has the ability to handle simultaneous requests.

When should you not use Node.js?

As you might have understood by now, Node.js shines on apps which are event-driven, data-intensive, I/O intensive and non-blocking. So what are the drawbacks of Node.js?

Heavy Computational Applications
The main drawback comes to the fact that Node.js is not able to do many calculations, i.e., it is not suitable for compute-intensive applications. Let’s say you’re writing a function which computes the Fibonacci number which is computationally intensive - what happens is that Node.js is unable to move on to the next thread because that heavy computation will block the single thread running in the application.

If your application requires a few heavy computing operations but benefits from Node.js' features in general, the ideal scenario is to implement the heavy computational task as background processes in another appropriate language. By using a microservices architecture, you’ll be separating heavy computational tasks from Node.js implementation.

In essence, Node.js shouldn’t be used for operations which are data calculations, processor intensive, and blocking because it simply doesn’t have the capacity to run them.

Although there are other open-source web development technologies, there really isn't a general principle to determine which technology can be applied for web and mobile app programming. If you need great performance, use Node.js, and if you need **high scalability, you can turn to other frameworks like Django. Being sure about what form of platform you want to build makes it easy to choose one.


All in all, Node.js' positions as a language designed with back-end programming in mind. Unlike general-purpose languages like Java or Python, its functionality is not unduly extensive since the runtime environment does not intend to cover a lot of niches simultaneously.

Want to read more about Node.js?

More than 500.000 people read our blog every year and we are ranked at the top of Google for topics such as Node.js. If you liked this blog post and would love to read all our blog posts on Node.js, press here.