React is the go-to technology, when it comes to developing FinTech apps – that’s for sure. But why do most FinTech companies decide to use it? What makes it such a good choice for creating applications that are compatible with a majority of devices? How can it help minimise costs of product development? Why do react developers love it so much? Answers to these and other questions are simple and easy to understand – everyone who invests in FinTech should know them, so we decided to explain everything in a blog post.

What it is and what it’s not

First of all, to understand why frontend developers love React so much, you need to understand what it is and how it works. Also, what its defining features are. The official definition says it’s a Javascript library dedicated to creating user interfaces. Despite a common misconception, it’s not a framework. What’s the difference?

The technical difference between a framework and library lies in a term called inversion of control. When a developer uses a library, they are in control of the flow of the application. They can choose when and where to call the library. When using a framework, the framework itself supervises the flow. It provides some space for the developer to plug in the code, but it calls the created code in when it’s necessary. In other words, libraries perform sets of specific and well-defined operations. Examples: network protocols, compression, image manipulation, generating particular visual elements. Frameworks are like skeletons of different shapes that define what the result should be (more or less) and that need to be filled out with content.

Also, a library can be easily replaceable by another library, but a framework cannot.

What libraries and frameworks have in common, though, is the fact that they are both pieces of pre-written code that can be used in order to build apps faster, without reinventing the wheel.

So, React is a library created with one major goal in mind: displaying data on screen.

Why React was born

React was invented when developing Facebook as an app cross-compatible with different systems became too troublesome. Making it work equally well on Android, iOS and UWP required parallel work of three independent teams of developers. But how much easier would it be to build this app in a technology that works with all of them? How much work hours and money could be saved?

React’s first prototype released to the public by Jordan Walke and called FaxJS was soon deployed on Facebook’s News Feed in 2011 and then implemented into Instagram in 2012. Later on, after the initial success, Facebook decided to make the whole framework capable of building whole apps on different platforms with React, React Native, but that’s a different story.

What React is perfect for

Right now, React is the most popular JS library and it’s definitely the best one for creating user interfaces of mobile applications and single-page applications (websites that can dynamically rewrite displayed content, instead of loading entire new pages).

Who loves React

Even though initially React was made by Facebook and for Facebook and Instagram, it quickly gained immense popularity. And for a good reason. The list of popular services built with React is long and starts with giants such as:

  • Facebook and Instagram
  • Netflix
  • Yahoo! Mail
  • Trello
  • Grammarly
  • Revolut Business
  • Cloudflare
  • WhatsApp
  • Dropbox

… and many more, if you’re interested in how such projects are made, just visit ReactJS web development company website.

What makes React so good for frontend development

We now know what React is, what it is perfect for and how popular it is, so let’s dive into some technicalities to find out what actually makes it so good, compared to alternatives.

  • Virtual DOMs

React is very flexible and makes apps and websites load faster, thanks to Virtual Document Models. Normally, DOMs are interfaces representing code as trees. Browsers use such models to render websites and whenever anything changes, they reload the whole document. React takes it a step further by creating a virtual copy of a DOM and observing it at all times. Whenever any changes are made, React notices them and only updates the rendered page where it’s needed, instead of reloading the whole screen. By updating the tree quickly, it saves noticeable amounts of computing power and time.

  • JSX (JavaScript XML)

Typical, legacy JavaScript syntax has some limitations that Facebook needed to get rid off to make React more efficient. One of such problems was that HTML code needed to be separated from JS code. By inventing JSX, Facebook allowed developers to mix them. In other words, JSX is an extension of typical JS syntax which allows for using HTML tags. It is not obligatory in React apps, but allows for a further increase of performance and productiveness in writing code.

  • Reusable components

React is component based. This means that developers can build encapsulated components that manage their own state and then just place them where needed to generate complete, complex user interfaces. Because these components are written in JS, they are independent fragments of code that can be reused in different elements of an app. It makes a developer’s work faster and updating easier, as modifying code of a component automatically yields changes whenever the component is placed.

  • Declarative style

Components are somewhat linked to the declarative style of React. Because they can be defined and reused, developers can design views for each state in an app and React will take care of updating and rendering what is needed whenever data changes. You simply need to declare what you want to show, instead of how to do it. Declarative views make code predictable and easy to debug.

  • Unidirectional data flow

Unidirectional data flow is not a React exclusive idea, but it may be somewhat exotic to some legacy JavaScript developers. Simply put, this concept is about passing data between different parts of an application in only one direction. In the case of React, it means that the state of an application is passed to “child” components, then the “view” is generated and users can perform their actions on this stage. Then, the actions can update the state and so on. The state changes only when actions take place. Such a level of control makes apps less vulnerable to errors and allows for faster debugging, because it’s easier to spot where something is going wrong.

The bright future of React 

React is being constantly updated and right now we’re waiting for its 18th revision. Such a number suggests a very fast pace of development and indeed, on average we get two major updates every year, each backwards compatible. The most interesting new feature React developers are waiting for is “concurrent rendering” which will allow React to generate multiple versions of the UI at the same time, working on several different state updates concurrently. To put it another way, even more performance and flexibility is coming!

Constantly rolling updates also meant that React is future-proof and secure. Right now, React’s popularity is soaring, so its community is getting more and more mature, too. Both the official documentation and third-party tutorials, books and other learning materials are in abundance and each day new ones are getting published, so it’s easy for developers to switch to React. React’s future is bright and only a new, major revolution can change it. What’s not to like?