Developers use React to create large-scale web applications that can change data without reloading the page. The core goal of React is to be quick, scalable, and user-friendly.
The whole development and maintenance of UI components are handled by a React.js developer. They create applications and front-end designs, application components, and user interfaces. And as any professional in software development, the best ones are not that easy to find!
React.js developer stats
If you think React.js would be the right software solution for your project, it doesn’t hurt to learn about some general statistics about developers well-versed in this framework and other compatible programming languages.
According to Stack Overflow’s 2021 report, React.js is now the most popular web framework, surpassing the second-rated jQuery by almost 6 percent. And this data is based on the response of 49941 professional developers, of which 19864 choose React as their most preferred programming framework.
The volume of respondents alone shows you the large number of developers that are fluent in this framework, although it is hard to determine how many React developers are there globally. But that doesn’t mean there is a surplus of good React devs: in fact, more than 8700 globally use it for their web development projects.
And when it comes to the cost of hiring a React developer, the hourly rates alone can get up to 60 dollars. Not to mention the cost of job advertising, recruitment, onboarding, vetting and the cost of disruption in your developers’ team until you find the best person for the job.
Interviewing a React.js developer
Tips for your pre-screen
The road to hiring an amazing developer full-time starts with a pre-screen call. This call is less focused on technical skills, and more on “weeding out” the candidates you deem unprofessional or simply not to be a good culture fit.
Our Head of Recruitment Nadya Pokhyla uses a practical approach to scoring candidates in pre-screens with a useful scorecard.
"I pay high attention to their professionalism, self-presentation and communication skills; as well as motivation, enthusiasm, English-speaking skills and many other important points we evaluate during pre-screen. I like to ask myself this question: ‘Would I work with this person as a colleague?‘"Nadya Pokhyla
Talent Acquisition specialist Evgenia Kashchuk adds:
"After conducting a lot of interviews, I can say that the main non-technical skills are presentability (everything starts with a call with a recruiter), openness, sociability, honesty, curiosity, flexibility."Evgenia Kaschuk
Top technical skills to look for in React.js developers
Since finding the best React.js devs can be a pretty daunting task (and costly too!), we’ve asked our recruiters and technical interviewers to help us pinpoint the most important skills they should possess, apart from great knowledge of React.js itself and their years of experience.
According to skilled React engineer and technical interviewer Terri Prifti, these are the three most important technical skills a React.js dev should have:
He adds that a great React developer should be familiar with:
- High Order Components (HOCs);
- Shallow rendering components;
- Being able to avoid prop drilling;
- Writing tests.
Talent acquisition specialist Catherine Fialkova underlines that “a good React.js developer should work with HTML tags, write CSS selectors, understand the box model and how to reset the border-box, and have an understanding of flexbox".
"Every React developer should also have an understanding of how Git is handled and have a profile on GitHub or GitLab. JSX is an abstraction of React. It is vital for a developer to have knowledge of this extension of HTML."Catherine Fialkova
Top non-technical skills in React.js developers
Some other qualities that you should consider when doing the first-ever interview with a candidate, according to Fialkova are:
- Clear and professional communication approach;
- Upper-Intermediate or higher English level;
- Ability to get on well with any team;
- Leadership ambitions;
- Ability to support and mentor the junior colleagues;
- Punctuality when it comes to attending the meetings or completing the tasks on time.
Interview questions to ask
- What are the features of React?
Expected answer: The important features of ReactJS are:
- One-way Data Binding
- Virtual DOM
- Why use React instead of other frameworks, such as Angular?
Expected answer: React outperforms Angular due to its virtual DOM implementation and rendering optimizations. Additionally, switching between React versions is simple since, unlike Angular, you don't need to install updates one at a time. Finally, various ready-made solutions are available to developers using React.
- What is an event in React?
Expected answer: An event is a potential action that might be brought on by a user or system-generated event. Events include mouse clicks, web page loads, key presses, window resizing, and other interactions.
- What are synthetic events in React?
Expected answer: A cross-browser wrapper for the native event of the browser is a synthetic event. It has the same interface as the native browser events, such as preventDefault() and stopPropagation(). However, the events are universally functional across all browsers.
- What is the difference between Hooks and Redux?
Expected answer: React Hooks features handle the local component state while Redux manages the global state and actions that can be dispatched.
- How do you manage folder structure?
Expected answer: React doesn’t have a rule on how you put files into folders, but some more common approaches are grouping by features or routes or grouping by file types.
- What is the React component lifecycle?
Expected answer: In React, each component has a lifecycle that you can track and control throughout its three primary phases. Mounting, updating, and unmounting are the three steps.
- How can you avoid component re-rendering?
Expected answer: To avoid re-rendering per component, you should use the shouldComponentUpdate() lifecycle.
- Give me three advantages of using hooks in React.
Expected answer: Using React Hooks provides three benefits: reusability, readability, and testability.
- How often does React useState update, and why?
Expected answer: React delays updating updates because developers utilize useState to improve speed by building queues. Candidates should be aware that useState updates happen asynchronously rather than immediately implementing changes to the state object.
- What is the biggest benefit of using Flux?
Expected answer: You can control how data flows through your program by utilizing Flux. You may more effectively analyze data changes and troubleshoot issues by adopting an unidirectional data flow with predefined responsibilities for each component (action, store, and view).
- How do you create refs?
Expected answer: React is used to build Refs. Using the ref attribute to attach to React elements after calling createRef(). When a component is created, refs are frequently set to an instance property so that they may be used as references throughout the component.
- How would you optimize performance in a React app?
- By keeping the component state local, when necessary
- By remembering React components should avoid needless re-renders
- By code-splitting with dynamic import
- Through React's windowing or list virtualization
- With React's lazy image loading
- What would you avoid binding in React?
Expected answer: I can use arrow functions in class properties to avoid binding in React. Class properties are a new feature and to use them, I must enable transform-class-properties.
- Tell us about previous projects you’ve worked on that were built on top of React.js.
Example answer: I have worked on a messaging app/real-time chat app/personal blog/e-commerce mobile application.
What sets apart a great React.js developer from a good one?
When it comes to the fine-tuned technical details that a great React dev could have, Prifti looks deep into the details of the code.
“I see all the differences in the import order, object destructuring, usage of memoized components, avoid defining functions inside render, usage of object literals.”
For Catherine, beyond mastering the expected tech stack, the most important criteria is that the developer can work without being supervised and reminded about their tasks:
“They should be able to present themselves and their work without constant supervision. Extra points if they take on more than only React-related tasks, have the agency to make their own decisions and a desire to learn new things.”
Why use React.js?
What is React used for?
What are the benefits of React.js?
Pieces of code available in React.js help reduce the amount of manual coding when creating standard dynamic UI components. If you are building a rich interactive web app, React.js will save you development time and help minimize errors and bugs. Moreover, React’s VirtualDOM will speed up your app’s page re-rendering in response to users’ actions and help provide a smooth user experience.
Is React only for single-page apps (SPA)?
Although in most cases developers use React to build SPAs the technology itself doesn’t limit you to the single-page app logic. You can implement a multiple-page logic for your web service by interlinking multiple self-contained react projects (pages) with your main application page. Apart from that, you can easily plug separate React components into any existing web application built with another technology.
Is React SEO-friendly?
When not to use React.js?
If you need to create a static website with a couple of basic dynamic forms or a simple SPA, choosing React.js would be overkill. If your project can easily be built using simpler tools, there is no need to choose React.js and overburden your code.
What companies use React.js?
React.js was initially created by Jordan Walke, a software engineer at Facebook in 2012. Since then Facebook’s web app has relied heavily on React.js. Same do the web versions of Instagram and WhatsApp.
What is the best backend for React?
Why and when should I use React instead of Vue?
React is a library whereas Vue is a framework. This means that React is a better choice if you need more freedom and control over your development process. You can customize it using a variety of companion libraries (like React-Redux) and solutions for styling (like JSS or Styled components). See our React vs Vue comparison.
React.js vs React Native
React is the base abstraction of React DOM for the web platform in React JS, whereas, in React Native, React is the basic abstraction of React Native. As a result, the syntax and workflow stay the same, but the components alter.
Which languages and frameworks is React compatible with?
Is React still popular?
React isn’t gonna be gone anytime soon! Due to its availability, wide community, vast library support and steep learning curve, web developers still use React.js far and wide.
It also makes testing easier, it is very dynamic and robust, and it is a highly productive language for many types of projects.
Some of the most famous apps developed in React are Facebook, Instagram, WhatsApp and Netflix are developed with React.js. Need more proof?
Checklist for finding the best React.js developers
If you need A-level React.js developers, apart from looking into the level React.js knowledge, you also need to check their familiarity with React frameworks and libraries, as well as their ability to use plugins on web pages.
You should also look into their experience with iOS and Android knowledge, ability to organize and document processes, and knowledge in performance optimization. Any experience in testing and debugging is an absolute plus since React applications also include a lot of these assurance phases.
Or, simply hire a React developer that works with Proxify!
What are the latest updates in React.js?
Developers will be able to use its stable and official release in the coming period.