When we hear about JavaScript, we typically think about the design of user interfaces we directly interact with: for instance, opening a browser and seeing pages, pictures, the search box, etc. This is the front end.
But JavaScript can be used for more than just the front end. Node.js is a popular open-source runtime environment that can execute JavaScript outside of the browser. Now programmers can use JavaScript for the back end as well, which means developing internal application logic that the ordinary user cannot see!
How does Node.js make this possible?
What is Node.js?
Well, Node.js is a non-browser JavaScript execution environment. It allows you to write code that uses the server itself — the physical machine that stores the data. Thus, with Node.js, JavaScript becomes a versatile tool both in the front end (visible in the browser part of the site) and in the back end (the code with which it is recorded on the server). A programmer can now use one language and engage in full-stack development.
Note that Node.js is not a separate programming language, but a platform for using server-side JavaScript. In other words, you take your familiar tool, JavaScript, and use a special program to extend its functionality. (Imagine that you have a screwdriver – by switching out the different bits you can drill a hole, screw in a screw, or grind a surface!)
Node.js is created using JavaScript, but it is also written in another programming language that is easier for the computer to understand. This combination of different languages allows the web server to appeal directly to the operating system without unnecessary delays.
What is Node.js for?
Before Node.js, applications written in JavaScript could only run in a browser. With the advent of the platform, it became possible to run JavaScript code on a server too!
A server is a physical machine for running service software. It’s primarily used to store and provide direct access to data. Developers also use servers for deploying websites, social networks, and applications, organizing VPN gateways, mining, and so on.
Front end and back end developers use Node.js to work with servers. It allows them to write a program for different operating systems (Linux, macOS, and Windows), as well as create cross-platform applications. They can also use it for application programming interfaces (APIs), which are designed to transfer data from one application to another. For example, a step counter app on your phone tells you how many steps you took today, then transfers that data to the calorie counter app. Based on this data, the calorie count app tells you how much you need to eat.
Node.js is at the heart of the Internet of Things (IoT). Simply put, the IoT is the concept of interconnected physical objects ("things") with the Internet and/or each other. They can collect and transmit data over a network without human intervention.
For example, when you wake up in the morning, your smart bed signals your coffee machine that you’re awake and it's time to make coffee. By the time you get to the kitchen, your coffee is ready, so you don't have to waste time making it. Smart devices communicate with each other without you being involved, making your life easier.
Node.js helps to manage devices and create servers capable of handling a large number of requests simultaneously. Moreover, Node.js is suitable for developing web applications that respond to user actions in real-time (RTAs). For example, it could be an online editor, such as Google Docs, that allows multiple users to work on a document at the same time. Also, it can be chat rooms (Zoom), social networks, and project collaboration systems (Miro).
How does Node.js work
When studying server processes, you need to know that there are two server schemes: multi-threaded and single-threaded.
In a multi-threaded application, the client requests the desired resource from the server and the server sends the resource in response. For example, you ask a seller to bring you a certain size of clothes, and the seller retrieves them, then brings them to you. The server needs a separate thread for each request. If there are more requests than threads, the server waits for one of the threads to become free. Imagine that you first asked for a dress and then decided to buy jeans. Each time, the seller grabs them and brings in the items one by one.
Node.js operates on a single-threaded approach. In this approach, all requests are handled within a single thread, and the web server doesn't waste time waiting for a response. It sends requests and processes responses as they arrive. In this way, the web server is always in operation rather than waiting. This makes efficient use of resources and allows commands to be executed much faster! (That is, now there is not just one seller going to the store to pick up a dress and jeans, but several. The buyer, on the other hand, does not have to wait for the seller to return. He can ask for another item at any time.)
Node.js uses an event-driven model, which allows you to react quickly to state changes, and a non-blocking I/O architecture, which makes it lightweight and efficient. This means that the main thread will not be blocked by I/O operations and the server will continue to serve requests. We are dealing with asynchronous programming, which allows you to execute a block of code without stopping the entire thread.
Let's take a step-by-step example of how a usual server and a Node.js server work! In this example, we need to upload an avatar and a background image to a website.
Reasons for Node.js popularity
High-speed
JavaScript code running in a Node.js environment can be several times faster than code written in other languages, like Ruby or Python, as they require more processing before reaching the computer core.
Node.js uses an asynchronous programming model. It allows you to continue processing other tasks without waiting for the data transfer to complete!
Many well-known companies have chosen Node.js as the basis for their platform: Walmart, Uber, eBay, GitHub, Netflix, Trello, Yahoo, and others. LinkedIn claimed a 20x acceleration of 27 servers after abandoning Ruby on Rails entirely in favor of Node.js back in 2012.
Versatility and flexibility
Node.js runs code written in JavaScript. This means that front end developers who already use JavaScript in a browser can write both client and server-side code in a familiar programming language, without having to learn the tool from scratch! In addition, JavaScript is a common language, so you can work on different projects if you know it.
You can write almost any application in Node.js and run it on Windows, macOS, or Linux. It is useful for developing universal applications, such as a task list that needs to work on all platforms, synchronize data in real-time, and be able to send everything to a mobile device. (Great examples are Todoist or Notion!)
Node.js appeared a long time ago, and over the course of its existence, a large community of developers has formed. The official Twitter account alone has over 800,000 followers. Most developers also use special forums and discussion groups.
Many modules and libraries
In Node.js, a module is a set of JavaScript functions and objects that can be used by external applications. Describing a piece of code as a module refers not so much to the code itself as to what it does. Any Node.js file or set of files can be considered a module if its functions and data are ready for use by external programs. Modules provide functions that can be used in larger programs. This is how modules open up the possibility of making their code available to other developers.
Suppose you want to make a pizza. You need dough, so you mix flour, eggs, water, etc. But the next person who wants to make a pizza will not repeat your steps – they’ll just buy it ready-made. That will be the module.
The Node.js ecosystem is growing rapidly thanks to the npm package manager. It is a clearinghouse for JavaScript code and the world's largest software registry. It contains over a million open-source modules and libraries. New ones appear all the time.
Running on the Chrome V8 engine
V8 is an open-source JavaScript engine. It is used in browsers based on Chromium. This means that Node.js works with most browsers, such as Chrome or the Android browser, and is supported by most operating systems. This makes it a relevant and marketable tool.
Node.js alternatives
Back end code can be written in any language. The difference is in the speed of development and reliability of the solution. Node.js applications can be written quickly, but it takes effort to ensure reliability. (Of course, Node.js has competitors!)
JavaScript code implemented in Node.js is inferior to PHP in popularity. The most popular content management systems, including WordPress, Joomla!, and Drupal, are written in PHP. WordPress alone runs about a third of all websites on the Internet. PHP's infrastructure is rather superior to that of Node.js. For example, PHP developers can choose between several decent web frameworks, such as Symfony, Laravel, and Yii2.
Python stands out as one of the best languages to learn to program. But the main difference between Python and Node.js is the application areas. Python is more universal: it is common in web development, data science, machine learning, and other areas. Node.js is more for web development. Thanks to Electron, which we will describe below, it is also used for desktop application development.
Node.js frameworks
Nevertheless, the Node.js infrastructure for JavaScript is mature, and developers have quality and user-friendly tools called frameworks.
Here are some of the most popular:
- AdonisJs — a framework that runs on all major operating systems. It has a stable ecosystem for writing server-side web applications
- Express — the simplest, most flexible, and fastest Node.js framework. It is suitable for the rapid development of simple applications, as it has easily accessible API generation tools
- Koa.js — was created by the Express.js team. Works across browsers with no callbacks and has a powerful error-handling system
- Electron.js — a framework for building desktop applications using JavaScript, HTML, and CSS. Allows you to maintain one JavaScript codebase and create cross-platform apps that work on different OS
- Nest.js — a framework for building efficient, reliable, and scalable server-side applications
I want to learn Node.js – where do I start?
Node.js is a super-minimalistic platform. All you need to know is JavaScript as well as the basic principles of web development, HTML, and CSS. This will help you link back end and front end development and start moving towards full-stack. Then you can read some pages of Node.js documentation and try to write a simple application in Node.js, preferably without frameworks.
You can become a developer through online and offline courses. TripleTen offers a convenient all-in-one solution for those who want to explore Node.js and other developer tools — Software Engineering Bootcamp. You will gain the knowledge and skills you need to move forward as a front end, back end, or full-stack developer.
However, it is important to remember that in addition to a certificate, a programmer must have a portfolio of real cases. It is much more valuable than just a diploma. TripleTen's Career Team can help you create a professional portfolio and be confident throughout your hiring process!
Node.js has its official website with detailed technical documentation. It is important for a developer to read the technical documentation because it gives a basic understanding of how the tool works. You can always find positive use cases or algorithms in it.
Node.js developer competencies and career path
Node.js developers are programmers who write their code to achieve all the functionality of a website or web application. It includes how the site is displayed in the browser (front end) and how it works inside (back end). This type of specialist is classified as full-stack. Once you master Node.js, your arsenal will include:
- Development of the user interface - front end
- Back end programming
- Connecting the database to the project and setting up the client-side and server-side integration
- Software deployment using manual and automated systems
- Testing code and correcting errors
- Preparation of technical documentation for other specialists
The average salary of Node.js developer in the U.S. is $121,375 a year or $58.35 an hour. Entry-level positions start at $102,500 a year while most experienced workers make up to $150,000 a year.
After mastering Node.js, you can continue learning extensions for JavaScript, such as TypeScript, Nest.js, and Angular.
In addition, as you progress from junior to middle and then to senior, you can take up management and become a development team leader. They no longer write code with their own hands and do not think about how to implement this or that function. Instead, they distribute the workload of the team, monitor the project, and take responsibility for the project as a whole.
Conclusion
Node.js is a powerful technology, which is worth exploring. It allows you to extend JavaScript and write both server-side code and interfaces in the same language. This greatly simplifies the developer's job and increases their chances of career advancement.
Node.js is popular because it is not difficult to learn, especially if you already know JavaScript. Also, Node.js has attractive future prospects, since today this technology is applied in the development of devices and applications that each of us uses in our everyday lives.