Why and When to Use Node.js in 2021 [Complete Guide] (2023)

In the bustling world of web development, choosing the ideal technology often sparks intense discussions. However, one solution that has consistently stood out from the crowd is Node.js. This powerful, JavaScript-based runtime environment has shaped the modern web landscape, enabling developers to build fast, scalable, and efficient web applications. But how do you determine the optimal scenarios and reasons for deploying this pioneering technology?

This guide explains why Node.js has become a go-to solution for developers worldwide. Join us in this exploration, where we clarify how to use Node.js and address burning questions like “What is Node.js good for?” and “When to use Node.js?” within the context of various development scenarios.

Table of Contents

The Essentials of Node.js: A Short Review

Node.js, an open-source, cross-platform JavaScript runtime environment forged from Chrome’s V8 engine, shatters the archaic limitations that once sequestered JavaScript within the browser’s boundaries. Its pioneering abilities pave the way for high-performance, scalable web applications. While understanding Node.js’s benefits and use cases is vital, such discernment requires a prior dissection of its architectural and operational mechanics.

Node.js Architecture: How It Works

The Node.js architecture rests on two key principles: non-blocking I/O operations and an asynchronous paradigm.

The first principle, non-blocking I/O operations, exemplifies how Node.js harnesses these operations to facilitate the smooth processing of client requests. This methodology enables the simultaneous execution of I/O operations without obstructing the main thread. The advantage of this approach is twofold: it markedly boosts efficiency while ensuring a higher degree of responsiveness.

The second principle, the asynchronous paradigm, illustrates the commitment of Node.js to an asynchronous programming model. This aligns seamlessly with the event-driven essence of JavaScript. With clever use of callbacks and event-driven programming, Node.js optimizes resource use and bypasses the potential bottlenecks inherent to synchronous operations.

These two principles, combined with JavaScript’s event-based model, underscore the importance of grasping the fundamental components of Node.js application architecture.

Basic elements of Node.js architecture

At its core, Node.js architecture is comprised of six critical elements:

  1. Requests: Incoming requests in a web application can be categorized as either blocking (complex) or non-blocking (simple), depending on the specific tasks users aim to perform.
  2. Node.js Server: It serves as the foundation of the architecture, functioning as a server-side platform. Node.js Server not only accepts requests from users but also diligently processes them, delivering corresponding responses.
  3. Event Queue: The Event Queue within the Node.js server acts as a storage mechanism for incoming client requests. It passes these requests, one by one, into the Event Loop for further processing.
  4. Event Loop: It represents an endless loop that perpetually receives requests from the event queue, processes them, and returns the appropriate responses to clients. This loop encompasses six distinct phases: timers, I/O callbacks, waiting/preparation, I/O polling, set Immediate() callbacks, and close events. These phases repeat until all code execution is completed.
  5. Thread Pool: The Thread Pool, a vital component of Node.js backend architecture, houses threads responsible for executing tasks necessary to process client requests efficiently.
  6. External Resources: External Resources play a significant role in handling blocking client requests. They are specifically designed to manage multiple blocking requests, such as data storage and computation, without impeding the overall system performance.

Understanding the functionality and flow of these components is paramount in Node.js application development. The modular architecture of Node.js, composed of these crucial elements, drives the success of applications built upon it.

Additional components of Node.js architecture

Additionally, Node.js encompasses other components that further enrich its architecture:

  1. Event Emitters: Node.js’ EventEmitter class is instrumental in creating and managing custom events, thereby bolstering the development of responsive, event-driven applications. It offers developers the latitude to define their own events that are triggered under specific conditions, leading to personalized and efficient applications.
  2. Asynchronous APIs: Node.js brings to the table a collection of asynchronous APIs that cater to various operations, such as file system access, network communications, and database queries. These APIs advocate for non-blocking code, which in turn facilitates efficient handling of concurrent requests, keeping the application performance optimized, even under heavy load.
  3. Modules: Node.js leverages a module system for organizing and reusing code effectively. Modules encapsulate related functionality, facilitating the development of modular applications. Node.js provides a comprehensive set of core modules, including HTTP, File System, and Crypto. Additionally, developers can create and utilize custom modules, promoting code modularity and maintainability.

Node.js also includes NPM (Node Package Manager), a robust package manager bundled with the platform. NPM grants access to a vast ecosystem of open-source libraries and modules, allowing developers to install and manage external dependencies easily. It fosters productivity and collaboration within the Node.js community.

There are more than two million packages in the npm registry

Also worth mentioning is Libuv – a core component of Node.js that supports asynchronous I/O operations. It’s a multi-platform C library that forms the essence of Node.js, handling multiple concurrent connections efficiently. With its event loop and non-blocking I/O model, Libuv ensures that Node.js stays lightweight and scalable.


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Top Benefits of Node.js

Node.js has swiftly emerged as a foundational pillar in contemporary web development. Its meteoric rise can be predominantly attributed to the extensive range of advantages it bestows upon its users. In the following discourse, we will explore the paramount advantages of Node.js and make a compelling case for why this runtime environment is commendable and an exceptional choice for many applications.

1. Scalability and Performance

Node.js was meticulously engineered with a steadfast focus on scalability and performance. Its groundbreaking event-driven and non-blocking paradigm seamlessly orchestrates the swift and proficient handling of a multitude of simultaneous requests. In addition, the formidable Google V8 engine, which drives Node.js, diligently compiles JavaScript into machine code, propelling lightning-fast execution.

2. Versatility and the Use of JavaScript

Node.js’s key strength is its support for server-side JavaScript, unifying client-side and server-side development, streamlining the process, and expediting development cycles. The widespread use of JavaScript further enhances Node.js’s appeal due to abundant resources, tutorials, and community support.

3. Code Reusability and Sharing

Node.js encourages code reuse and sharing. Thanks to npm, developers can package their solutions into modules and share them with the community or import packages created by others to avoid “reinventing the wheel.” This principle of code reusability can drastically shorten development cycles and promote maintainable and clean code.

4. Rich Ecosystem

With npm, Node.js boasts the world’s largest ecosystem of open-source libraries, providing many ready-made solutions and packages that can significantly expedite the development process. This vibrant ecosystem fosters continuous innovation and collaboration, adding an element of communal support that developers worldwide cherish.

5. Microservices Architecture

Finally, Node.js reigns supreme as the ultimate choice for building applications within a microservices architecture. Its lightweight nature and modular design make it easy to break down complex applications into simple, decoupled, and manageable microservices. This can significantly improve application flexibility, resilience, and scalability.

In summation, it is pivotal to perceive Node.js as more than just a runtime environment. It is an all-encompassing solution tailored to contemporary web development’s dynamic needs.

Disadvantages of Node.js

While Node.js has reshaped the web development landscape with its wide array of advantages, it’s equally important to acknowledge its limitations. Discussed below are some of the significant challenges that come with the use of Node js.

1. Single-Threaded Nature

Node.js operates on a single-threaded model, which is highly efficient for handling multiple concurrent connections. However, this architecture proves to be a bottleneck when dealing with CPU-intensive tasks. Since all operations share a single thread, any CPU-bound task can potentially block the entire thread, leading to performance degradation. Therefore, Node.js may not be the best choice for applications that involve heavy computations or processing.

2. Inconsistent Quality of Packages

The npm registry, while being an enormous repository of reusable code, does suffer from inconsistencies in the quality of packages. Not all packages are rigorously tested, well-maintained, or properly documented. This can lead to potential reliability and security issues, making it essential for developers to carefully vet packages before integrating them into their applications.

3. Challenges with Relational Databases

Node.js interfaces superbly with NoSQL databases, like MongoDB, but struggles somewhat with SQL databases. The lack of mature libraries for handling SQL queries can introduce challenges for applications that rely on relational databases. As a result, developers may face inefficiencies in their code and potential performance bottlenecks.

4. Complexity of Asynchronous Programming

Asynchronous programming, which is a fundamental part of Node.js, can pose a steep learning curve for developers accustomed to synchronous programming. Debugging asynchronous code, managing callbacks, or handling Promises and async/await patterns can be complex and lead to messy code if not managed well. This could potentially slow down the development and compromise code quality.

What is Node.js used for?

Node.js has a broad array of applications due to its flexible and efficient nature. Here are some of the most common Node.js use cases you must know:

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Real-time Web Applications

In light of its remarkable event-driven, non-blocking architecture, Node.js dominates the landscape of building real-time web applications, encompassing the likes of instant messaging and gaming applications. It efficiently handles multiple concurrent requests, making it perfect for situations where updates need to be instantly reflected across multiple users.

Chatbots and IoT Applications

Node.js stands tall in scenarios that require low latency and high data-intensive capabilities. These features make it a prime candidate for dealing with the torrential data rates of IoT devices while also providing smooth and swift conversational experiences in chatbots.

Collaborative Tools

Collaborative tools, like Trello or Google Docs, require real-time synchronization of data across users. Node.js, with its capability to handle numerous connections concurrently, is aptly suited for developing such applications.

Single-page Applications and Dynamic Websites

Node js is used for building single-page applications and dynamic websites due to its ability to handle multiple requests asynchronously. It can serve dynamic content to users, improving the overall user experience.

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Streaming Applications

An area where Node.js truly demonstrates its prowess is in the development of streaming applications. Its capacity to effectively manage data streams makes it an ideal choice for such projects. Node.js has the notable ability to process files during the upload process, a feat that effectively trims down the overall processing time.

Microservices and APIs

Node.js’s lightweight nature makes it a fitting choice for developing microservices architectures and RESTful APIs. It allows for applications to be split into smaller, manageable modules that can be developed, tested, and deployed independently.

In conclusion, Node.js is a powerful tool with a diverse range of applications, from real-time web applications to microservices. It provides developers with the features and capabilities needed to build scalable, efficient, and dynamic web applications, thereby reinforcing its place as a highly valued asset in modern web development.

Examples of Node.js Apps

The robust features and capabilities of Node.js have attracted a multitude of high-profile corporations and startups alike. Many popular applications we use daily are built using Node.js. While Netflix, LinkedIn, PayPal, and Uber are among the most famous, let’s examine some other impressive applications that owe their success to Node.js.

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Walmart, the largest retail corporation globally, adopted Node.js to serve its web and mobile platforms. The company decided to switch to Node.js for its server-side to efficiently handle the massive volume of customer traffic during Black Friday sales. The switch to a microservices architecture using Node.js enabled Walmart to provide a seamless, scalable shopping experience, even during peak traffic times.


Trello, a popular project management application, is another notable example of a Node.js application. Trello uses Node.js for its server-side, ensuring efficient handling of a large number of open connections for real-time updates, which is a critical feature in Trello’s functionality.


Medium, a renowned blogging platform, uses Node.js to serve millions of stories to its users every month. The use of Node.js has helped Medium scale its services efficiently, handling a vast amount of requests while maintaining a fast and responsive user experience.


eBay, one of the largest e-commerce platforms worldwide, opted for Node.js to maintain live connections with browsers and to increase the speed of their application. The event-driven, non-blocking nature of Node.js has provided eBay the ability to handle large volumes of user requests in real-time, thereby improving the user experience significantly.


Perhaps surprisingly, NASA turned to Node.js to keep astronauts safe during space missions. Node.js usage helps NASA to implement a microservices architecture, ensuring data related to any aspect of a mission is always available and accurate. The move to Node.js led to a reduction in data access times by a significant margin.

Learn more about big companies that use Node.js and discover why they choose this technology.

In summary, these Node.js uses illustrate technology’s versatility for many industry leaders, regardless of the sector. From e-commerce platforms to blogging sites, from project management tools to space expeditions, Node.js provides an efficient, scalable solution to various software development needs.

When Not to Use Node.js

As efficient and versatile as Node.js may be, it is not a silver bullet for all development scenarios. There are certain situations where the use of Node.js may not be the best choice. Let’s dig into the circumstances where the application of Node.js might not be optimal.

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CPU-Intensive Applications

Node.js operates on a single-threaded, event-driven loop to handle multiple concurrent clients effectively. While this is excellent for I/O-intensive tasks, it’s not well-suited for CPU-intensive tasks. Applications that involve heavy computations, like image and video processing or machine learning algorithms, can block the event loop, leading to performance degradation. In these cases, languages like Java, Python, or C++ might be better suited.

Relational Databases

Node.js shines with NoSQL databases, but if your project heavily relies on a relational database, you might face some inefficiencies. Libraries for handling SQL queries in Node.js are not as advanced or intuitive as those for NoSQL databases. If your application’s core functionality is built around complex transactions and SQL queries, you might want to consider other technologies, like Ruby on Rails or Django.

Simple HTML and CRUD Applications

While Node.js is certainly capable of building simple CRUD (Create, Read, Update, Delete) and HTML applications, it might be overkill. If your application doesn’t require real-time data, scalability, or non-blocking features, a simpler framework like Flask for Python or Laravel for PHP might be a quicker and more efficient choice.

Lack of Experience

JavaScript, while popular, is also notorious for its quirks and can be tricky to master, especially when dealing with asynchronous programming and callback hell. If your team isn’t well-versed in JavaScript and the nuances of the Node.js application development process might be more challenging and time-consuming than it needs to be.

Large and Monolithic Applications

Node.js shines when it comes to microservices or service-oriented architectures. However, for large, monolithic applications, managing and scaling with Node.js can become challenging. In such scenarios, other robust technologies, such as Java or .NET, might be more suitable.

When Strong Object-Oriented Programming is Required

While JavaScript does support object-oriented programming (OOP), it does not provide the level of support seen in languages that are fully object-oriented, such as Java or C++. If your project heavily relies on strong object-oriented principles, it might be better to consider these alternatives.

In conclusion, while Node.js is a powerful tool for many applications, it’s essential to remember that no single tool can be the best choice for every job. Careful consideration of the project’s requirements and the technology’s strengths and weaknesses will ensure that you select the right tool for the job, whether that’s Node.js or alternative technology.

Other Considerations to Remember When Choosing Node.js

Embarking on a project with Node.js at its core is a decision that carries several critical considerations that can impact the overall success and feasibility of your implementation. So, let’s dig deeper and explore key factors that mustn’t be overlooked:

  • Scalability and Performance Subtleties: A system’s scalability and performance depend on effectively applying clustering, load balancing, and caching strategies. These components bolster a system’s ability to manage increasing user demand and boost overall performance. By paying meticulous attention to these aspects, you can stave off potential system bottlenecks and address the burgeoning needs of a growing user base.
  • Security Considerations: While Node.js has inbuilt security mechanisms, it’s fundamentally important to go beyond these provisions. Complementing the natural security features with meticulous, secure coding practices and other security safeguards fortifies your application and guards against prevalent vulnerabilities.
  • Code Organization and Structure: Node.js projects can quickly become complex, especially as they grow in size and functionality. Establishing clear code organization and structure is vital, following best practices and design patterns. This ensures maintainability, readability, and scalability as the project evolves.
  • Learning Curve for Asynchronous Programming: Node.js heavily relies on asynchronous programming, which can be a paradigm shift for developers accustomed to synchronous programming. Understanding concepts like callbacks, Promises, and async/await is crucial to leveraging Node.js effectively. Be prepared for a steep learning curve, especially for developers new to asynchronous programming.
  • Hosting and Deployment Factors: Node.js applications require a server environment to run. It’s important to consider the hosting options that support Node.js, such as cloud platforms or dedicated servers. Additionally, deployment strategies, continuous integration, and delivery pipelines must be planned to ensure smooth deployments and efficient release management.
  • Monitoring and Debugging Tools: Effective monitoring and debugging are essential for maintaining the health and performance of your Node.js application. Familiarize yourself with the tools and frameworks that help with application monitoring, error tracking, and performance profiling. This will aid in detecting issues, optimizing performance, and ensuring a smooth user experience.

To successfully execute your Node.js projects, hiring a skilled Full-Stack Developer is essential. Discover how to find the right talent by visiting our blog post on hiring Full-Stack Developers.

Summing Up

Selecting Node.js for your project requires a deep understanding of its intricacies, something that experienced professionals are equipped with. If you’re fortunate already to have a proficient Node.js developer on the board, you’re sitting pretty. However, if you need to bring in more Node.js developers to strengthen your team, consider Relevant as your first choice.

At Relevant, we specialize in building scalable solutions, skillfully leveraging the strengths of Node.js, and tackling challenges head-on. We keep our fingers on the pulse of the industry, ensuring that, as our client, you’re always at the cutting edge with access to the latest tools, advanced methodologies, and the industry’s best practices.

Choosing Relevant as your software development partner brings our vast expertise to your table, enabling you to unlock the full potential of Node.js and deliver outstanding outcomes. Don’t delay your success—reach out to us, and we will transform your digital presence together.


What is Node.js used for?

Node.js is a versatile runtime environment that allows developers to build fast and scalable network applications. One may ask, “Why use Node.js?” The answer is simple – it’s exceptional for data-intensive real-time applications, APIs, microservices, and streaming applications.

What does Node.js do that makes it a standout in the world of technology?

Rooted in Chrome’s V8 engine, Node.js delivers excellent performance by executing JavaScript server-side, elegantly merging front and back-end development. Its non-blocking, event-driven model guarantees streamlined functionality, ideally suited for data-laden, real-time applications.

What are some notable Node.js uses, and what can you do with this platform?

From creating APIs and building real-time web applications like chats and gaming servers to enabling efficient microservices architectures and serverless computing – Node.js has an extensive list of uses. It’s this adaptability that has made Node.js a favorite among tech giants like LinkedIn, Netflix, and Uber. So, if you’re asking, “What can you do with Node.js?”, our answer is, “Nearly everything”.

When and why should I use Node.js for my application?

The ‘when’ and ‘why’ to use Node.js fully hinges on your project requirements. If your app requires real-time data, involves heavy I/O operations, needs single-page app features, or demands high-speed rendering, Node.js is the right choice. Its fast execution, event-driven architecture, and ease of scalability make it well-suited to these types of applications.

What is Node.js, and what distinguishes it from JavaScript?

Node.js serves as a runtime environment, enabling JavaScript execution beyond the limiting scope of a web browser. While JavaScript has traditionally been used as a client-side scripting language, Node.js enables its use on the server side, effectively expanding the capabilities of JavaScript. Therefore, it’s not that Node.js differs from JavaScript, but rather that it amplifies its functionality.

Is Node.js good for the backend?

Absolutely! Node.js has transformed the landscape of back-end development. Its non-blocking, event-driven architecture leads to efficient and scalable applications. Additionally, using JavaScript for both front-end and back-end development offers better consistency and efficiency – a feature that’s made Node.js app development a darling of back-end developers.

When should I consider using Node.js for my project?

Comparing Node.js vs. other server-side technologies, Node.js emerges as a formidable contender with its lightning-fast processing and scalability. So, Node.js application development is a top choice for real-time applications like chat, collaborative tools, or gaming.

What are the benefits of using Node.js compared to conventional server-side solutions?

Node.js outperforms conventional server-side technologies due to its high-performing, scalable, single-threaded, non-blocking architecture. It brings JavaScript to the server side, unifying the web development language. Its vibrant open-source community simplifies feature addition through an expansive ecosystem of libraries and frameworks.

Which industries or domains commonly use Node.js?

The purpose of Node.js is to provide an efficient platform for building fast, scalable network applications that have led to its adoption across various sectors.

Tech and IT services: Node.js serves as a keystone for building scalable applications and APIs.
Finance and Banking: Entities like PayPal leverage Node.js for effective concurrency and swift data processing.
Media and Entertainment: Platforms like Netflix depend on Node.js for handling high traffic and quick rendering.
E-commerce and Retail: Node.js answers the sector’s need for real-time updates and prompt request handling.
Logistics and Transportation: Giants like Uber appreciate Node.js for real-time tracking and scalability.
Across these industries, the shared need is for swift, scalable, and efficient software solutions, and Node.js web development consistently meets these requirements.

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