What is Node.js?

Node.js is an open-source JavaScript runtime environment based on Google's v8 engine. It was created in 2009 by Ryan Dahl and has since grown in popularity immensely — it boasts a huge, active community and the largest package registry in the world with over a million packages and growing every day.

Many companies shared their use cases showing that Node.js is a great tool for speed and cost optimization for every company. Plenty of those case studies have proved that thanks to Node.js you can improve the speed of your application and at the same time reduce server and operational costs!

But why is that? What gives Node.js such an advantage? First of all, contrary to other technologies that are multi-threaded, Node.js basically works on a single thread. It uses event-driven, non-blocking I/O — thanks to that main event loop never blocks and it can constantly accept new connections, making it extremely scalable.

Of course, Node.js is not a silver bullet. We need to remember that the single-threaded nature of Node.js comes at a cost. If you are planning a CPU-heavy system, it might not be the right tool for you. But if you are planning to move your monolith architecture to microservices, or you need great scalability, multitasking, and real-time communication — Node.js sounds like the perfect tool for you!

What can you build in Node.js?

Node's purpose was always to create highly scalable network applications. This was achieved thanks to its event-driven, asynchronous I/O architecture, making it possible for an application to handle tens of thousands of simultaneous requests at once.

With the constant inflow of new features, Node has been quickly conquering many new, previously unthinkable fields. For example the recent introduction of threads to Node's core has enabled the implementation of operation-heavy AI/machine learning algorithms.

Streaming applications are a perfect use case for Node.js. It has a built-in Stream API that e.g. allows transmitting parts of the application to a local machine without closing the connection — which means that new parts can be easily downloaded on-demand or in the background.

Real-time applications, also known as RTAs, are a really common case for using Node.js. For those applications' end-users, performance is a really important thing and Node.js handles the heavy input-output operations extremely well.