JavaScript programmers are engaged in the interfaces of Internet services. For this purpose, there is a special library - React. Those who know how to work with it are called React developers.

• Who is a React developer and what do they do
• Developers responsibilities
• Required knowledge and skills
• How much do React developers earn
• How to become a React developer
• Where specialists can work
• Expert adivce

Who is a React developer and what do they do

A React developer is a programmer who specializes in front-end development using the React library for JavaScript. They are responsible for creating user interfaces efficiently and effectively, which are the interfaces that visitors interact with on websites and services.

Since React is a library rather than a programming language, job titles may not always explicitly mention React, but instead may list it as a requirement in the job description. Therefore, you may come across job postings for frontend developers with React skills rather than specifically for React developers.

While React is not the only tool available for building interfaces, it is widely used by many companies. Some may opt to use pure JavaScript or other libraries and frameworks like Angular. However, React remains a popular choice, making React developers in demand across various industries.

It is the responsibility of the React developer to ensure that all interactive elements on the screen function properly and display up-to-date information, including weather, traffic, and currency exchange rates.

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Developers responsibilities

• Using HTML and CSS according to the designer's layout to create the visual appearance of the interface accessible to the user.
• Making pages dynamic using JavaScript code and React tools, describing the functionality of buttons, forms, and other interactive elements.
• Ensuring interaction with the server-side of the website or service: sending user-entered data there and receiving the results of their processing.
• Testing interface code, fixing errors, and optimizing the service's performance.

Required knowledge and skills: First and foremost, a React developer needs to know HTML, CSS, and JavaScript — the "minimal set for a frontend developer". They should be able to build and make web pages interactive using these tools. Typically, specialists who consider React development already possess these skills.

Knowledge of the React library itself is necessary — its features, patterns, and tools. React has quite an extensive toolkit, numerous additional libraries, and advanced features that allow for automation and the creation of more sophisticated interfaces. All these nuances are documented, but it's better to learn their application in practice, for example, in a "React Developer" course.

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Required knowledge and skills

First and foremost, a React developer needs to know HTML, CSS, and JavaScript — the "minimal set for a frontend developer". They should be able to build and make web pages interactive using these tools. Typically, specialists who consider React development already possess these skills.

Knowledge of the React library itself is necessary — its features, patterns, and tools. React has quite an extensive toolkit, numerous additional libraries, and advanced features that allow for automation and the creation of more sophisticated interfaces. All these nuances are documented, but it's better to learn their application in practice, for example, in a "React Developer" course.

It happens that a developer first learns React and then gradually delves into JavaScript, HTML, and CSS. However, without these skills, it is impossible to work effectively as a React programmer.

In modern development, code versions are used, so the ability to work with Git — a version control system, and collaboration tools like GitHub will be needed. It's important to understand how these systems work, how to upload code to them, and navigate other developers' code.

A React developer needs to be able to test code. Typically, this is the responsibility of testers, but some basic tests fall on the programmers' shoulders. Specialized tools like React Testing Library are used for this purpose.

At each career stage, a developer's required knowledge and skills are divided into levels:

• Junior Developer Requirements: Basic knowledge of React, JS, HTML, and CSS. Ability to work with Git.

• Middle Developer Requirements: Deep immersion in React, learning additional libraries and testing tools.

• Senior Developer Requirements: Thorough knowledge of all React features. Ability to work with other JavaScript libraries and frameworks. Knowledge of design patterns, algorithms, and data structures.

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How much do React developers earn

React developers and frontend developers with entry-level React knowledge can expect to earn starting from $70,000. More experienced professionals can anticipate salaries ranging from $120,000 to $200,000.

On glassdoor.com, the salary for a senior-level React developer starts from $120,000–$300,000. To earn this much, deeper knowledge is required, and sometimes skills in working with other frameworks are necessary. Therefore, it's no longer accurate to simply call them React developers.

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How to become a React developer

1. Learn the basics — HTML, CSS, and JavaScript. Practice creating functional interfaces without using React to understand the general principles.
2. Learn Git and collaboration tools for code collaboration.
3. Master the basic skills of a developer. Understand the principles of writing clean code.
4. Learn React. Read its documentation, try applying it in practice, and study related libraries. React has states, or state, which are used to pass and fix changing data. You need to know how to manage states, for example, using the Component State/Context API.
5. Understand application state management. For this, there are libraries like Redux, MobX, and Recoil.
6. Learn TypeScript. It is a scripting language based on JavaScript with static typing, allowing for more efficient work with data of different types.
7. Master working with APIs. This is necessary for interacting with the backend. The best fit for this is REST API, and later you can delve into other technologies.
8. Understand testing. Learn its general principles, how to use tools and frameworks like React Testing Library and Jest.

You can start working as a junior React developer after the first four steps, but for further development, it's essential to study the following items.

For advancing as a React developer, you can use this roadmap. After mastering the React library, it's worth trying to write your first application using it to practice your skills in practice.

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Where specialists can work

React and JS developers are needed:

• In companies that develop their own online services and websites. These can be media companies, marketplaces, banks, retailers, online education services, and any other businesses present on the internet. Typically, large companies hire developers internally to maintain their products and do not engage third-party agencies for this purpose.
• In companies that create websites and services on demand. They work on various projects for companies that do not want to build their own team of developers and entrust their internet services to outsourcing companies.

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Expert advice

40.5% of website developers use React in their work — this is according to research conducted by Statista. In this article, we will explore what React is, the problems it solves, and what makes it popular.

• Why React is Needed: Helps Create Interfaces
• How React Works: Describing What We Want to Achieve
• React's Popularity: 24 Million Installations Per Day
• What Makes React Great: Universality, Flexibility, and Excellent DevX
• Learning React Should Start with HTML and JavaScript

​Why React is Needed: Helps Create Interfaces

React is characterized as a JavaScript library dedicated to crafting user interfaces. Let's dissect this definition.

JavaScript (JS) stands as the solitary programming language responsible for delineating the behavior of elements on a web page within the browser, thereby imbuing interfaces with interactivity. Consider these straightforward instances of JS functionality:

• A click event triggers the opening of a popup window—this exemplifies JavaScript.
• Publishing content on Instagram without the need for page refresh upon clicking the 'Publish' button also underscores JavaScript's capability.

For example, in Google Docs, JavaScript operates as follows:

A comment in Google Docs appears without refreshing the page — this is possible thanks to JavaScript.

A library is code written by other developers. Although React is often referred to as a framework, this is not entirely accurate: developers use code from a library in their program, while a framework incorporates the developer's code within itself. Let's provide an analogy:

• A library is like a garage with cars, scooters, bicycles — you can take any transportation and go wherever you want.
• A framework is like a bus in which passengers can be seated to travel from point A to point B.

A framework restricts the developer's choice of tools but ensures that common tasks are solved in a standardized way according to quality standards. On the other hand, a library does not dictate which technologies to use, what to create, and how — this simplifies learning and provides more flexibility, but places responsibility on the developer for the code and tools chosen.

User interfaces are what the user sees on a website, mobile app, VR glasses, chatbot, smartwatch screen, and so on.

Now that we've clarified the definition, let's discuss why React.js is needed and how to use it.

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How React Works: Describing What We Want to Achieve

To understand how React works and what its feature is, you need to understand two approaches to programming: imperative and declarative. Let's do this with the example of a taxi.

• If a passenger tells the taxi driver: turn the wheel to the right, and now to the left, press the gas pedal, then the brake, this is the imperative approach. The passenger describes each action of the driver to get a result (to get home).
• But if the passenger gives the address and the taxi driver plans the route, follows the transmissions and turns, this is the declarative approach. The passenger describes the end result (the point to arrive at) and the response to external events like "if we get stuck in traffic for an hour, drop me off at the metro station."

React.js operates on the idea of a declarative approach. It's called "UI as a function of data" - the developer describes how the interface behaves depending on data and events, for example:

• for each user in the chat, draw a cross button in the list with avatars;
• if a user clicks on the cross, remove the user from the list, next to whose avatar this cross is.

With React, developers don't have to describe the details. Let's compare the solution with a library and without for this task: removing a user from the chat list if another user clicks on the cross next to them.

Without the library

Specify that when removing a user from the list, the text next to their name, the button next to the avatar, the avatar itself, and the data should also be removed from 20 other places where there is information about the deleted user.

With React

Pass a list of two users instead of three. And React will redraw all elements on the page.

Descriptions of UI blocks in React.js become components, from which the interface is assembled. Components are forms, buttons, fields, and screens of the application. The developer creates them themselves or takes them from third-party libraries. Moreover, they can nest components within each other, reuse them, or edit them all at once:

• the developer describes the component using React;
• specifies all the places where this component is displayed;
• React adds components to HTML;
• if the developer needs to modify the component, for example, change the color of the button, they specify a new color for the desired component;
• React changes the color of all buttons, in all places where this component is displayed. Moreover, it's possible to make the button color customizable for each specific component.

The trick is that creating and configuring components are separate processes. First, the developer describes how the component looks and behaves, for example, a button, and which properties can be configured. Then they place button configurations in different places, for example: in a form - medium green, in the cart - large yellow, on the main screen - small gray.

You can compare how the code for the same popular application - a to-do list - looks like if you use JavaScript without libraries or JavaScript and React.

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Popularity of React: 24 million installations per day.

React was developed by Facebook 13 years ago, which is now called Meta. But now React is an open-source project, to which every developer can contribute changes. And it's popular not only among the Zuckerberg team:

• 40.14% of website developers used React in 2021 - it's the most popular library for creating user interfaces;
• React has 220k stars on GitHub;
• 40.58% of developers want to learn React;
• 24 million times users installed React - that's in one week from March 1 to 7, 2024. For comparison: the closest competitor in terms of installations - Vue - had five times fewer installations during the same period - 3.4 million installations.

Let's not bother counting how many times React has been installed over five years.

*Number of installations of various libraries over the past five years. React is represented by the orange line. Data from npmtrends.com.*

Developers use React for various interfaces, such as:

• In many user-facing and internal services of Salesforce.
• For the feeds of websites and applications of Facebook and Instagram.
• In the BBC news.
• On Tesla, Airbnb.
• In the WhatsApp messenger, and many other interfaces, a detailed list is available on GitHub.

React is used in browsers, smart TVs and watches, mobile applications, virtual reality glasses, console applications, and chatbots. Everywhere. And it's easy for developers to understand: if they need to switch platforms, they won't have to start learning a new technology from scratch. Instead, they can take familiar React and adapt it to the local interface.

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What Makes React Great: Universality, Flexibility, and Excellent DevX

React has four advantages over similar libraries for interface development.

Versatility. React is a JavaScript library, and JavaScript is a popular programming language used everywhere. No other JS library works in as many environments and on as many devices.

Flexibility. React is flexible because it allows you to:

• choose which libraries to use, for example, for managing screen transitions and data storage;
• change development tools;
• build the entire application with React;
• or use it for just one feature. The choice is yours.

Excellent DevX. UX is user experience, and DevX is developer experience — how convenient, comfortable, and easy it is for developers to interact with the technology. And React offers excellent DevX.

React has been around for 13 years, and during this time:

• solutions have been found for all typical problems;
• thousands of tools have been developed to make the developer's life easier;
• a huge and constantly growing ecosystem has been formed around the library. All this makes React convenient for developers. And there are many users of the library — which means there are people to learn from and ask for advice.

Readability. In React, the application is divided into components, so in 9 out of 10 cases, when something breaks, you can see where the problem is:

• the developer sees that the button is broken;
• goes to the "button" component and fixes the problem for all buttons at once. If something breaks in JavaScript, the developer usually starts crying. Because the problem could be on the HTML side, or on the JS side, or at the intersection of these technologies when there is a "data-display desync". Often there is no clear separation into files, you have to dig. And most importantly, fixing one button won't automatically fix the rest.

And in pure JavaScript, you can write beautifully documented and efficient code, which is why libraries appear. And in React, you can write poorly readable code with bugs, but the library itself makes this task more difficult. If a developer has to write complex, convoluted code to solve a typical problem in React, they are doing something wrong and it's time to consult a search engine.

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Learning React should start with HTML and JavaScript

First, you learn the basics — HTML, CSS, and JavaScript, and only then move on to React. Learning in a different order is illogical, much like studying technical English without a language foundation — it's painful and slows down development. After mastering the basics, you can move on to learning React, for example, starting with the official React tutorial.

To accelerate progress when learning React.js, feedback and code reviews are helpful. Thanks to code reviews, the code becomes functional, readable, and meets industry standards. Therefore, it's better to learn React with a mentor or within an educational group.