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How to Build Real-time Application with Node.js

Node.js is a flexible platform. However, one of its predominant use cases is real-time applications. This article will focus on some of the particular facts that are important to consider while building Node.js-based real-time apps.

Uber is one of the first Node.js adopters. Its core trip execution engine was originally written in Node.js because of its asynchronous primitive, simple, and single-threaded processing. Therefore, it’s safe to say that Uber was one of famous companies to deploy Node.js technology in production to build a reliable system for its passengers and drivers. As a result, the company has successfully processed over 2 million remote procedure calls (RPCs) per second post Node.js implementation. It gives Uber the ability to manage large quantities of concurrent connections hassle-free.

Similarly, tech giants like LinkedIn and Netflix have used this technology at different stages to deliver modern and scalable applications. The main reasons for leveraging Node.js are as follows:-

  • High performance– The page loads within seconds.

  • Common programming language – They can use the same language for both the server-side and client-side.

  • Ease of use – A straightforward way of writing, debugging, and engineering the API.

To summarize, Node.js can quickly process a significantly large amount of data and provide convenient analysis and quicker code deployments. Now that we have a basic knowledge of Node.js and its benefits let’s understand how it can fuel real-time application development.

Common Challenges: What are the Challenges in Building Real-Time Apps?

From web apps to business applications, the user’s primary necessity is to get updates and stay on top of things. However, many companies get stuck while building real-time web apps at the initial stages because they are not aware of the challenges they might encounter during real-time web app development.


Scalability is the main challenge development teams face while building real-time web apps. Each request of a refreshing query every 5 seconds needs a whole set of database queries. It works fine with ten users; however, it collapses under hundreds of users. Moreover, it’s also important to consider the right toolset for your application. The developers are responsible for designing data flow, events, and integration points from the scaling perspective.

Node.js offers viable solutions in terms of scalability to many big companies like Netflix, Walmart, Uber, PayPal, etc. For example, LinkedIn has 467 million users in over 200 countries. The company replaced its synchronous Ruby on Rails mobile app in which clients used to make several calls for a single page, with an asynchronous event-based system. The team decided to use Node.js owing to its scalability and performance efficiency, and it proved to be the right approach for them.


When it comes to real-time data streaming platforms, it’s necessary to consider the complete workflow’s security aspects. For example, live streaming applications need to integrate with existing security layers to support SSO (Single Sign-on) and control access to data and systems based on the user’s role.

The platform should also support data protection, including data encryption at rest and data in motion, and algorithms’ intellectual property. It can be challenging when algorithms are accessible on a cloud system or running on edge devices. It is because many analytics platforms operationalize algorithms as scripts or unpackaged codes.

Finding the right data format, development frameworks & schemas

Streaming is typically real-time. In real-time apps, stream data processing is only one aspect of its overall functionality. This streaming data finds its way to a large-scale data repository, either on-premise or cloud-based. Analysts and domain experts use it to extract insights, understand trends, and develop algorithms applied in real-time to data streams that enhance operations and extract business value. The structure of data and tools that analysts, data scientists, and domain experts have at their disposal can impact the entire platform’s adoption and application. Following are some stats that will help you understand the popularity of video streaming in the past and future:

  • According to Statista, in 2020, users globally spent more than 480 billion hours watching live streaming content, especially on mobile devices.

  • As per this report by Cisco, the video will make up 79% of all mobile traffic by 2022.

Streaming data consists of a series of time-stamped data packets. Therefore, developers should search for tools for processing time-series data. This way, it makes it easy to clean, visualize and explore patterns. These tools also provide a development framework necessary for the streaming process. It can make the development and deployment of algorithms to the operating system more efficient and less error-prone.

To avoid developing costly predictive maintenance algorithms, it’s best to use system simulation tools to generate synthetic data, which supplements real data in developing algorithms.

Node.js architecture for real-time apps

The workload is one of the most popular reasons to scale applications. That’s where Node.js comes into play. It provides scalability to increase the availability and tolerance to real-time app failure. As a result, Node.js has become one of the best programming languages to build real-time apps due to its event-driven and asynchronous nature.

Node.js-based real-time apps use single-threaded event loop model architecture to handle multiple concurrent clients. On the other hand, technologies like JSP, Spring MVC, ASP.NET, HTML, AJAX, and JQuery follow multithreaded request-response architecture to handle multiple concurrent clients. But, Node.js architecture makes it different from other technologies. The single-threaded event loop architecture possesses the following advantages:

  • It easily handles more and more concurrent client requests.

  • Apps based on Node.js use fewer threads to utilize only fewer resources or memory.

  • An app based on Node.js gets more concurrent client requests; therefore, there is no need to create more threads due to the event loop.

  • Due to its architecture, Node.js gets concurrency and asynchronism characteristics.

The main idea behind adopting this architecture is that a single main thread can perform and scale much better under typical web loads with comparatively conventional “one-thread per request” architecture. That’s why: Node.js is the go-to option for many since it has advantages in terms of scalability and speed for real-time apps.

Socket.IO & its use cases

If we’re talking about real-time apps, we can’t forget to mention Socket.IO, a JavaScript library, an essential ingredient for building real-time applications. Since it enables bi-directional communication between web clients and servers. It also consists of two parts: client-side library and server-side library. A client-side library runs in the browser and a server-side library for Node.js Socket.IO, enabling real-time bi-directional event-based communication.

You may be aware that Node.js has a module called, which handles constant communication between the client and the server, and allows the server to push real-time updates to clients. framework makes it easy to implement Socket and is available for iOS, Android, backend, and front-end. It is an excellent tool for developers wanting to set up bi-directional socket connections between client and server. It makes simple apps such as live chat much simpler to implement.

Use Cases of Socket.IO for real-time apps

Multiplayer Gaming Application

The multiplayer gaming app with two or more players is a use case of Socket.IO. It’s impossible to make HTTP or HTTPs calls to develop the real-time multiplayer gaming app because their packet size is more prominent. On the other hand, these calls’ packet sizes are prolonged. In such cases, the Socket.IO library is best to send and receive data to and from the server. What’s more? Socket.IO library is fast and capable of sending only those data packets which are needed. So, using only HTTP programming, you will not be able to create any multiplayer gaming app or application that requires interacting with a server on a real-time basis.

Single-Page Applications (SPAs)

SPA is a web application that fits on a single page on the browser. Such an app dynamically rewrites the current web page rather than loading the whole new page. As a result, users can experience a similar experience as a desktop app. SPAs are widely used to build social networking apps and project management tools. Google and Gmail are popular examples of single-page applications. Basically, it consists of only one page with all downloaded content initially, and since it is lightweight, much work is performed on the backend rather than calling information directly to and from the frontend. Single Page Applications usually run on JavaScript (Angular, React, or Vue framework) on the frontend and Node.js on the backend.

Twitter is another popular application that runs smoothly with JavaScript and Node.js. Similarly, Netflix’s adopted Node.js to transform its website into a single-page application. Java supports the backend of Netflix while Node powers its user interface.

Video Conference Apps

Node.js is a great choice for developing video conference streaming apps. Videos typically work with streams. In simple terms, a backend does not send the entire video at once, but a video is sent as a set of smaller chunks. Finally, it ships the whole video. That’s why video buffers while watching a video on slow broadband since it only plays the chunks it has received and tries to load more.

The bottom line is that Node.js is also a great choice for building conference/ video streaming apps. It sends data in small chunks that are sent to the frontend piece by piece rather than in a huge single package. It lets users process the files while they are still uploading.

Real-time chat app

In a real-time chat app, when one user, suppose ‘A’ is typing something, then the other user, ‘B’ should know that ‘A’ is typing. This is the crux of a real-time chat application. WhatsApp and Facebook Messenger are two popular examples of real-time chat applications.

If we use HTTP calls in such apps, the other user ‘B’ will never see the other user’s status because of the delay. To overcome this problem, Socket.IO comes into play. With the use of Socket.IO, when user ‘A’ types anything, his/her device will send only one data packet, which will inform the server that he/she is typing. Therefore, it will be delivered to another user, i.e., B. In other words, with, when the server receives a new message, it will send it to the client and inform them.

During real-time chat app development with Socket.IO, the entire process speeds up and reduces the data transfer.

Common Features to Include During Real-time App Development

The famous companies like WhatsApp, Slack, Nest, Zendesk, Twitter, and more depend on real-time experience powered by real-time technology. Also, on-demand food delivery apps like Deliveroo enable users to order food on-demand and track it in real-time.

As a business owner of a real-time app, you will be left behind if you do not offer such an experience.

To enhance your user experience, we’ve put together a few important features that will give you an edge over your rivals. Let’s have a look!

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