Toptal is a marketplace for dedicated React.js developers, engineers, programmers, coders, architects, and consultants. Toptal helps CEOs, CTOs, and management at top companies find React.js developers for their mission critical development projects.
Barbara is a full-stack developer specializing in front-end development with expertise in React frameworks. Her passion is bringing user experiences to life. She was a software architect (C/C++) for point-of-sale terminals. Barbara designed and developed Verifone's Vx Contactless Card Payment app, which performs contactless card-based transactions used worldwide. This background provides her with a strong foundation in software engineering, development tools, and teamwork.
Tushar has 14+ years of experience building scalable internet services ranging from B2B SaaS, eCommerce, and mobile to consumer software platforms. He's an expert in Ruby on Rails, Node.js, Golang, React, and JavaScript. He has worked as a hands-on engineering leader at startups that went public or valued over $1 billion. Tushar's passionate about working on various types of projects and with new people.
Travis is a seasoned software developer and tech lead with over 11 years of professional experience. He is highly skilled in a wide range of programming languages and web technologies, with nine years of expertise in React and Node.js and seven years working with Elixir and Phoenix. A fervent advocate for web performance, Travis has an almost obsessive passion for optimizing Core Web Vitals to deliver faster, smoother user experiences.
Andrew is a passionate full-stack developer with 20+ years of experience. He specializes in React development and is a talented UI designer with great attention to detail. Over the years, his apps have been used by hundreds of thousands of people. Andrew prides himself in his leadership skills, creating apps from concept to deployment, and is primarily interested in opportunities that involve React.
Joshua is a software engineer with 11 years of experience specializing in React, React Native, and Node.js development. He has created a wide range of applications and websites while working as an engineer, including 12 gambling apps for a leading iGaming company. Joshua works in a clear and organized manner, ensuring that projects are well-planned before he starts programming. He contributes exceptional value as projects progress from start to finish.
Stefan is a developer with 5+ years of commercial experience specializing in front-end and mobile development, conceptual design, planning, and prototyping. His technical expertise includes React, JavaScript, TypeScript, and Node.js. Stefan's industry experience is backed by a bachelor's degree in business informatics. A Certified Scrum Master, he is fascinated by technology and its possibilities and is highly motivated to leverage it to deliver customer and business value.
Eric is a front-end developer with 5+ years of experience. He has specialized in React for three years and has strong knowledge of JavaScript, including the newest features in ES6+. Eric delivers well-documented, readable, and clean code, and he is fluent in CSS/SCSS and CSS in JavaScript, including styled components and Material-UI. His industry experience is backed by a bachelor's degree in applied mathematics and computer science.
Iswan is a web and mobile application developer with over nine years of experience and extensive knowledge of front-end JavaScript. He has significant experience with frameworks and libraries such as React, React Native, and Redux. Having worked on projects in various industries, including real estate, eCommerce, livestock auction operations, and government services, Iswan is adept at applying the right technology solutions to the correct problems.
Teddy is a full-stack software engineer. He has experience as a developer, lead developer, and teacher. Previously, he had the opportunity to work on projects at scale in industries like eCommerce, media, or networking. He started his freelance journey in 2018 and has since had the opportunity to work on several Back-End and Front-End applications. Teddy enjoys focusing on writing code but also automation, software architecture, and, more generally, quality.
Rahul is a professional software engineer with leadership experience and expertise in building full-stack React and Node.js applications and streaming data analytics solutions. He has designed and developed an innovative context-aware advertising platform using Node.js and machine learning techniques, which the Silicon Valley-based data analytics company acquired later.
Vivek is an experienced software engineer working in the information technology and service industries. Skilled in React, React Native, Flutter, Vue.js, Node.js, Express.js, PHP, Laravel, and Java, he is eager to work on hybrid web/app development and loves being part of or leading teams. Vivek believes in continuous learning and implementing the best possible solutions.
React, also known as ReactJS or React.js, is a JavaScript library that is designed to build interactive user interfaces. Its flexibility and ease of use make it one of the most popular tools among front-end developers. This guide provides you with the knowledge and tools for identifying and hiring a skilled React developer.
... allows corporations to quickly assemble teams that have the right skills for specific projects.
Despite accelerating demand for coders, Toptal prides itself on almost Ivy League-level vetting.
Our clients
Creating an app for the game
Leading a digital transformation
Building a cross-platform app to be used worldwide
Drilling into real-time data creates an industry game changer
Testimonials
Tripcents wouldn't exist without Toptal. Toptal Projects enabled us to rapidly develop our foundation with a product manager, lead developer, and senior designer. In just over 60 days we went from concept to Alpha. The speed, knowledge, expertise, and flexibility is second to none. The Toptal team were as part of Tripcents as any in-house team member of Tripcents. They contributed and took ownership of the development just like everyone else. We will continue to use Toptal. As a startup, they are our secret weapon.
Brantley Pace
CEO & Co-Founder
I am more than pleased with our experience with Toptal. The professional I got to work with was on the phone with me within a couple of hours. I knew after discussing my project with him that he was the candidate I wanted. I hired him immediately and he wasted no time in getting to my project, even going the extra mile by adding some great design elements that enhanced our overall look.
Paul Fenley
Director
The developers I was paired with were incredible -- smart, driven, and responsive. It used to be hard to find quality engineers and consultants. Now it isn't.
Ryan Rockefeller
CEO
Toptal understood our project needs immediately. We were matched with an exceptional freelancer from Argentina who, from Day 1, immersed himself in our industry, blended seamlessly with our team, understood our vision, and produced top-notch results. Toptal makes connecting with superior developers and programmers very easy.
Jason Kulik
Co-founder
As a small company with limited resources we can't afford to make expensive mistakes. Toptal provided us with an experienced programmer who was able to hit the ground running and begin contributing immediately. It has been a great experience and one we'd repeat again in a heartbeat.
Stuart Pocknee
Principal
How to Hire Remote React.js Developers through Toptal
1
Talk to One of Our Industry Experts
A Toptal director of engineering will work with you to understand your goals, technical needs, and team dynamics.
2
Work With Hand-Selected Talent
Within days, we'll introduce you to the right React.js developer for your project. Average time to match is under 24 hours.
3
The Right Fit, Guaranteed
Work with your new React.js developer for a trial period (pay only if satisfied), ensuring they're the right fit before starting the engagement.
Capabilities of React.js Developers
Our developers leverage React’s component-based architecture, virtual DOM, and state management to build dynamic, responsive, and performance-optimized user interfaces for clients seeking bespoke front-end solutions that will scale as their business grows.
Custom React.js Application Development
React’s dynamic nature makes it a popular library for developing complex yet responsive front-end solutions. Toptal developers harness the scalable capabilities of React.js to build high-performing web applications and seamless user experiences tailored to your unique business needs.
Maintenance and Upgrades for React.js Applications
Continual support, updates, and performance enhancements ensure long-term scalability as your business grows. By staying proactive in addressing issues and upgrading features, our developers guarantee that your applications will evolve seamlessly to meet changing requirements and technological advancements while remaining robust, stable, and secure.
Performance Optimization
Techniques such as lazy loading, code splitting, and memoization smooth user experiences in React.js applications by improving load times and overall responsiveness. Our developers create optimized and high-performing applications that boost user satisfaction by strategically minimizing unnecessary resource consumption and delivering content dynamically.
Single-page Application (SPA) Development
SPAs in React.js deliver a streamlined user experience while promoting efficient data handling, vibrant interfaces, and optimal navigation. Toptal developers excel in crafting fast, responsive SPAs, prioritizing smooth user interactions and minimal load times as content is loaded swiftly onto one dynamic page.
API Integration and Data Fetching
Libraries for API integration and data fetching are critical for handling real-time data efficiently and powering dynamic, responsive user experiences. Toptal developers seamlessly integrate React.js applications with back-end APIs, using libraries like Axios or GraphQL to ensure that their applications deliver up-to-date information.
Testing and Quality Assurance
Tools like Jest, React Testing Library, and Cypress are paramount to robust testing strategies, such as component validation and end-to-end testing. Our developers conduct thorough testing to ensure their applications are reliable and bug-free, maintaining the highest standards for quality assurance throughout the development process.
State Management
State management tools like Redux, MobX, and React’s Context API are vital for effectively handling intricate application states across various React components. Our developers use these libraries to architect robust applications with data consistency, complex user interfaces, and streamlined user experiences.
Cross-platform Development With React Native
React Native extends the advantages of React.js to mobile, enabling cross-platform development for both iOS and Android applications via a shared codebase. Leveraging their React knowledge, Toptal developers build and deploy mobile apps, reaching a broader audience while maintaining code consistency and a unified UX across devices.
Component-based Architecture
React’s component-based architecture facilitates streamlined development, clearer code organization, and easy maintenance of large-scale applications. By breaking interfaces down into modular, self-contained components, our developers proactively craft reusable, manageable UIs that can be repurposed for different parts of an application or shared across related projects.
Server-side Rendering (SSR)
Incorporating server-side rendering (SSR) frameworks into your React application bolsters SEO and accelerates content access for users. Utilizing frameworks like Next.js, Toptal developers achieve superior server-side rendering capabilities that efficiently pre-render content, leading to faster and more satisfying page loads.
Find Experts With Related Skills
Access a vast pool of skilled developers in our talent network and hire the top 3% within just 48 hours.
At Toptal, we thoroughly screen our React.js developers to ensure we only match you with the highest caliber of talent. Of the more than 200,000 people who apply to join the Toptal network each year, fewer than 3% make the cut.
In addition to screening for industry-leading expertise, we also assess candidates’ language and interpersonal skills to ensure that you have a smooth working relationship.
When you hire with Toptal, you’ll always work with world-class, custom-matched React.js developers ready to help you achieve your goals.
What is the no-risk trial period for Toptal React.js developers?
We make sure that each engagement between you and your React.js developer begins with a trial period of up to two weeks. This means that you have time to confirm the engagement will be successful. If you’re completely satisfied with the results, we’ll bill you for the time and continue the engagement for as long as you’d like. If you’re not completely satisfied, you won’t be billed. From there, we can either part ways, or we can provide you with another expert who may be a better fit and with whom we will begin a second, no-risk trial.
How much does it cost to hire a React.js developer?
The cost associated with hiring a React.js developer depends on various factors, including preferred talent location, complexity and size of the project you’re hiring for, seniority, engagement commitment (hourly, part-time, or full-time), and more. In the US, for example, Glassdoor’s reported average total annual pay for React.js developers is $151,000 as of June 2024. With Toptal, you can speak with an expert talent matcher who will help you understand the cost of talent with the right skills and seniority level for your needs. To get started, schedule a call with us — it’s free, and there’s no obligation to hire with Toptal.
How quickly can you hire with Toptal?
Typically, you can hire a React.js developer with Toptal in about 48 hours. For larger teams of talent or Managed Delivery, timelines may vary. Our talent matchers are highly skilled in the same fields they’re matching in—they’re not recruiters or HR reps. They’ll work with you to understand your goals, technical needs, and team dynamics, and match you with ideal candidates from our vetted global talent network.
Once you select your React.js developer, you’ll have a no-risk trial period to ensure they’re the perfect fit. Our matching process has a 98% trial-to-hire rate, so you can rest assured that you’re getting the best fit every time.
How do I hire a React.js developer?
To hire the right React.js developer, it’s important to evaluate a candidate’s experience, technical skills, and communication skills. You’ll also want to consider the fit with your particular industry, company, and project. Toptal’s rigorous screening process ensures that every member of our network has excellent experience and skills, and our team will match you with the perfect React.js developers for your project.
Can you hire React.js developers on an hourly basis or for project-based tasks?
You can hire React.js developers on an hourly, part-time, or full-time basis. Toptal can also manage the entire project from end-to-end with our Managed Delivery offering. Whether you hire an expert for a full- or part-time position, you’ll have the control and flexibility to scale your team up or down as your needs evolve. Our React.js developers can fully integrate into your existing team for a seamless working experience.
Kevin is a full-stack developer with more than 20 years of experience working with JavaScript. He has worked in various industries, from aerospace and marketing to indie games, and is the former Managing Editor of Technical Content at Toptal. Kevin ranks in the top 2% on Stack Overflow.
React (also known as ReactJS or React.js) is one of the world’s most widely used JavaScript toolkits for building user interfaces (UIs). As of June 2024, more than 45 million live websites were using React on their front end: Beyond Meta’s own Facebook, Instagram, and WhatsApp, other leading enterprises like Uber, Airbnb, Shopify, Netflix, and Amazon also rely on React developers to achieve their business objectives. This means React is central to the technology landscape for modern applications. With more than a decade of maturity behind the platform and Meta’s vested interest in actively maintaining and improving it, React is not only the front-end framework of choice for many seasoned professionals, but also the default recommendation for novices.
According to the State of JavaScript 2022 survey, React has shown strongly rising popularity since 2016 and was listed in the survey’s “A” tier for retention and continued use among developers who had tried out the package. Growing steadily more popular since its release, React was downloaded almost 25 million times as of June 2024, according to npm trends. As a result, React developers remain by far the most dominant group when it comes to front-end hiring trends, per May 2024 Hacker News Hiring Trends data. Having a steady pool of React developers for hire (from among millions) provides many opportunities for companies who need them—too many, in fact.
With such a high demand, finding the right freelance React developer for your project requirements can be an enormous challenge. This guide highlights the key qualities to look for as you hire React programmers and will help you carry out your hiring process to find the right person for your organization and project.
What Attributes Distinguish Quality React Developers From Others?
Broadly speaking, React developers create and maintain code that works with the React framework to produce the visible part (i.e., the front end) of a website or app. For smaller projects, companies may rely on a React developer to cover adjacent responsibilities too—everything from UI or user experience (UX) optimization to accessibility assessments, graphic design, SEO, and even back-end development (in the case of a full-stack role). Larger projects will engage specialists in such aspects, leaving React developers to concentrate on leveraging their core skills; an extensive skill set is needed to use React to produce the high-quality, responsive UIs the framework is famous for.
Core Competencies for React Developers
React experts can describe the best practices they employ and how these techniques make a noticeable impact on the reliability and overall ROI of a project as they bolster code quality. The following general qualities and soft skills are important to look for when hiring React developers:
Mastery of the React ecosystem — Broad familiarity with the React ecosystem saves company time, allowing developers to leverage trustworthy third-party libraries and tools rather than coding them from scratch. React experts should be familiar with React design patterns, hook-based techniques, and debugging tools. In addition, mastery of state management libraries like RxJS lets developers maintain and scale their web apps as feature complexity grows. Their extensive experience with the React component life cycle and methods like shouldComponentUpdate allows rendering optimization and side effects management, minimizing bugs and ensuring optimal application performance.
Library management and component reusability focus — React is especially well suited for developing libraries of reusable class components. When you hire React.js developers, look for candidates with excellent library management skills and extensive experience developing components in React that can be reused across teams and projects.
Testing React applications — Building a continuous integration or deployment environment in which every pushed commit is automatically tested—and, if successful, deployed—has become standard practice. Conducting unit and integration testing helps to catch bugs before they happen, building user trust and boosting revenue. When it comes to testing, React has many libraries available, and candidates should have familiarity with one or more of the popular options, such as Jest (based on Jasmine), Mocha, or Karma, as well as the ReactTestUtils library.
Design thinking — Design thinking is important for everyone involved in development, but it’s especially important for React programmers who build UIs. Even when working with dedicated UI and UX designers, React experts must have a profound understanding of modern design principles to craft effective and responsive UIs. As a contributor to the webpage’s front-end development, a React engineer’s job often consists of transforming a designer’s wireframe into functioning, deployable code.
Problem-solving and attention to detail — ReactJS programmers have to solve many problems and manage complexity while building modern UIs, which typically make use of multiple toolkits, packages, and components and interact with a variety of back-end systems. Moreover, while attention to detail and its consequences for code quality is important for all software engineers, front-end software directly impacts UX, and even the tiniest flaws will be clearly visible to users and customers.
Communication skills and understanding business goals — As part of a development team, a React developer for hire has to be able to work well with peers, seniors, and juniors. The give and take of roles, from requirements through quality assurance, necessitates professional and responsive communications at all times. Moreover, developers must understand that commercial applications exist to fulfill business objectives. Web and mobile app developers have to keep their organization’s business requirements in mind throughout the development process.
Complementary Technology Skills for React Developers
Given that React is a front-end web technology, React programmers are required to have several standard front-end skills to ensure a seamless user experience on your app. The following skills and programming languages are in addition to the wider ecosystem of common JavaScript tools, such as Babel, ESLint, and webpack:
HTML5 and CSS3 skills, along with Document Object Model (DOM) mastery — Since a substantial percentage of React applications will be deployed on the web and will interact with HTML and CSS, React developers must understand these standard web technologies. HTML defines the internal hierarchy, called the DOM of a webpage. One of React’s strengths is its ability to map a virtual DOM to the real DOM. Understanding the DOM is essential for React developers. CSS code defines the styles used by webpage elements, regardless of whether they’re static or dynamic.
JavaScript — At its core, React is a JavaScript library: JavaScript is the scripting language React is made in, and is what makes React applications dynamic and interactive by modifying the DOM and communicating with servers after the page has loaded. React also comes with a language created specifically for it called JSX, which is a way of combining the syntaxes of JavaScript and XML (similar to HTML) to create compact, readable definitions for both class components and functional components. All candidates should have a deep understanding of JavaScript fundamentals, such as variables, objects, and functions, as well as software development concepts like conditional statements and iterating through datasets.
Angular, Vue.js, and other alternative toolkits — While React is an excellent toolkit, sometimes other toolkits such as Vue.js and Angular may provide superior components and results when used in combination with React, along with specialized React developer tools. Skills in alternative frameworks may not be an absolute requirement, but having a general idea of how they work helps candidates understand different methodologies, making them more adaptable developers with a broader toolkit they can use to solve problems.
Redux — Managing state in React can be difficult, especially as applications grow in size and complexity. Larger React codebases can benefit from the well-organized approach that Redux—an open-source JavaScript library that centralizes state management—provides. This is especially true of apps that have a lot of global application states to manage, frequent state updates, and/or complex state update logic. The Redux project provides related tools like Redux Toolkit, which helps React developers follow state management best practices, and the Redux DevTools Extension, which vastly simplifies the troubleshooting and inspection of internal data flows via powerful features like time travel debugging.
Mobile and cross-platform deployment skills — React is also used for mobile applications, so iOS, Android, and other mobile app development skills will often be necessary depending on the nature of your project.
Git — Even the smallest project needs source code version control, and Git remains the most popular tool for it. Unless your organization uses an alternative like Mercurial or SVN, the React developers you hire will need at least basic Git skills, and your team would be well advised to establish an overall Git strategy (such as enhanced Git flow) if it hasn’t already. If your team is growing but lacks someone with advanced Git skills, consider vetting your React developers for this as part of your hiring process.
How Can You Identify the Ideal React Developer for You?
While it’s desirable to find a candidate whose skills and experience match the general qualities listed above, when hiring a dedicated or freelance React developer, you also have to consider your company- and project-specific needs and conform to your business process for hiring. If you try to hire React engineers without an awareness of the specific skills gap they’re meant to fill on your team, you’re relying on chance to provide you with a good fit. At best, you may waste time pursuing someone to underuse their skill set; at worst, you may hire an underskilled developer and place excessive expectations on them, leading to frustration rather than successful projects.
Before you search for candidates, it’s best to have a clear and realistic view of your project requirements and the impact you expect your new hire to have on your team:
How far along is your React project? Adding a few features to a mature app is much more straightforward than creating a project from scratch, which requires senior-level expertise and architectural abilities. For a short-term project just needing support to get to the finish line, you may not need to hire dedicated ReactJS developers; instead, consider outsourcing to freelance candidates working on a project basis.
Which technologies—besides React—does your project rely on, and what are the additional skill requirements? For example, if this is going to be a web-only project, the candidate doesn’t need mobile app experience.
Who will your new React developer work with, and in what capacity? If your organization needs to combine front-end and back-end experience in a single developer, you’ll want to hire top full-stack experts whose expertise includes both React and your back-end tool set. You may also seek front-end specialists to refine your UI.
Will your new hire receive React-specific mentorship or be expected to provide it? Junior developers’ productivity is driven by oversight, while top ReactJS developers thrive on independent work.
In addition, every sector has its own special needs. Look for skilled developers whose portfolio contains engagements that match the type of application being built. An e-commerce front end is naturally quite different from a database search front end or a dating platform front end.
React Developer Experience Levels
Another important consideration is React engineer seniority and experience levels. When hiring a sole developer or filling a lead slot, you will generally want to find the most experienced senior developer available. But sometimes the budget may constrain your options, and when hiring for a team role, a junior developer can often provide just the right skills at better pricing. Apart from years on the job, different skills distinguish junior and senior ReactJS developers.
Junior React developers have one to three years of experience and are proficient with the most important React skills, including building reusable UI components with JSX, using props to pass data, managing component state, and unit testing React components with libraries like Jest and React Testing Library. They’ll have some skill with more recent ECMAScript standards (from ES6/ES2015 through ES2024), allowing them to structure JavaScript code in cleaner, more efficient, and more readable ways with features like destructuring, template literals, and arrow functions. They can use CSS to style reusable components in React and create basic interactivity via useState hooks. Junior developers are comfortable working in an Agile environment and completing routine tasks, such as adding small features to a preexisting app, and might require supervision to understand and conform to team coding standards without introducing bugs.
Mid-level React developers have three to five years of experience and can perform more advanced tasks, such as building more complex and dynamic UIs, optimizing components, and integrating external APIs. Their state management experience includes the more capable approaches that RxJS, Redux, and MobX provide, so that state from disparate app components (e.g., options and user authentication) is handled properly regardless of app usage patterns. Working on larger apps has honed both their skill with React Developer Tools and their ability to design architecture in a way that promotes code reusability using patterns like hooks and composition to keep their code readable and maintainable. This is also true of their approach to routing and navigation: They’re equally comfortable working on single-page applications or traditional ones, and handling nested routes and dynamic parameters to allow navigation structures that match the complexity they need as an app’s feature set grows. For many projects, they can be trusted to turn sets of business goals into entire applications without much outside assistance and can provide mentorship to junior developers.
Senior React developers have more than five years of experience and can tune and scale large, complex applications. They know how to keep an app performant using techniques like code-splitting via lazy loading, dynamic imports, and both React.memo-style and useMemo-style memoization. They can design scalable applications and are experienced with containerization and deployment strategies using Docker or Kubernetes. Their experience with React design patterns like container/presentational components lets them refactor React applications as needed and ensure codebases are well suited for automated testing, which is essential for reducing bugs and avoiding their recurrence. They use unit tests, integration tests, end-to-end tests, and tools like React Testing Library, Jest, or Enzyme to ensure the robustness of new releases. They also know how to speak the language of back-end developers to ensure that integration is seamless between the front and back ends. Senior ReactJS developers are the leaders of the development team, defining the architecture for React apps, mentoring junior developers, communicating with stakeholders, and leading code reviews in order to maintain a high level of quality in the final product. They are comfortable wearing multiple hats, performing project management and design duties, and may eventually move into leadership roles or co-found startups.
How to Write a ReactJS Developer Job Description for Your Project
The keys to writing a good job description for a React developer are clarity and priority. The text must communicate your needs clearly and should specify key skills, the nature of the position (whether you seek junior or senior, fixed-term or permanent, on-site or remote ReactJS developers) along with other basic features of the role, like salary range. For a freelance React developer role associated with a particular project, the job description should make the project and its scope clear as well because you’ll be looking for someone whose past experience matches that particular project as closely as possible. It’s also worth including the structure of your team so candidates will have an idea of the level of support they will have, the time zones of team members, and how they will collaborate with colleagues.
Within the description, your most important needs should be listed up front and marked as mandatory requirements for applicants. Certainly, React expertise is the main focus, but if you already know additional packages and toolkits that will be used, those can be listed as nice-to-haves. If you want someone to take charge of a React development project, or if you’re hiring a team contributor, say so up front. List any relevant soft skills, such as leadership or conflict management. If the role touches on any other major technologies, you’ll want to include relevant parts from their job templates too. For example, a full-stack role might be for a project already hosted on Google Cloud Platform, Azure, or Amazon Web Services (AWS).
Finally, should you write “React,” “React.js,” or “ReactJS”? Officially, it’s “React,” but advertising that your development company would like to hire React.js developers rather than React developers won’t deter any worthwhile candidates, who are used to seeing some varied nomenclature.
What Are the Most Important React Developer Interview Questions?
Since React development processes rely heavily on common web technologies, a good React developer interview will not only include React interview questions—and discussions of relevant best practices—but also ones about JavaScript, HTML, CSS, and any other technologies your next project may happen to rely on. The answers to these technical questions should be evaluated by skilled React experts.
However, before starting the interview process, it is important to ask, “What strategies can a hiring manager implement to verify a candidate’s past work experience, React proficiency, and reliability?”
Before Getting Started: How Do You Evaluate a Candidate’s React Experience?
In addition to assessing a React developer’s technical abilities during the interview, you may wish to analyze the candidate’s CV and portfolio, examine their digital presence (e.g., social media and blog posts discussing React), and check their employer references. It can be useful to recruit the assistance of an in-house React expert to verify the candidate’s experience across these areas and during the interview.
The candidate’s CV should make clear which of their past assignments used React and to what extent. Recent assignments should come with links to websites or apps crafted by the candidate. The candidate should be able to explain their visible contributions to those sites and apps in detail. If a candidate uses GitHub, their projects visible on this platform should make use of React. However, it’s entirely possible for a legitimate React expert to have few visible projects if they’ve been working primarily on closed-source projects. In that case, cross-check their portfolio against previous employer and colleague references.
During the interview, the candidate should demonstrate confidence in their responses to pressing questions about React experience and be able to detail the nature and scope of their work on past assignments. Additionally, take-home assignments or technical questions are useful in assessing the React developer’s level of expertise. These should focus on skills relevant to the project that will be used on a day-to-day basis. It is a good idea to start with more basic questions focusing on UI design, HTML/CSS, and JavaScript fundamentals before moving on to more complex topics like state management and local styles.
What are React’s strengths and weaknesses? How do you play to its strengths, and how do you shore up its weaknesses?
All toolkits have strengths and weaknesses. A skilled React developer will know how best to use the framework and when to use other tools alongside React. Some commonly mentioned issues with React include that on its own it is only a toolkit and not a complete framework; it has a steep learning curve; issues exist with JSX (which React relies on); and there are issues associated with debugging complex React projects. The question allows the candidate to demonstrate their knowledge about React in broad terms. Keep in mind each of the strengths and weaknesses that the candidate lists; these are good starting points for discussions about specific functionality.
Explain the difference between stateful and stateless components and describe the situations in which one or the other type is preferred.
This is an example of a detailed technical question a React developer should be able to answer with ease. Stateful components manage information over time, handle complex application logic, and interact with an application’s back end, while stateless components are best for presenting ephemeral information to end users. Candidates should have a deep understanding of state and state management, as it is very common in web development.
What are higher-order components (HOCs) in React? How do you use them?
Skilled React developers, particularly mid-level and above, should have knowledge and real-world experience using HOCs because they promote code reusability, maintainability, and separation of concerns. HOCs are functions that take a component as their argument and return a new one; in essence, they are wrappers. They can be used to extend or modify the behavior—including the rendered output—of the contained component. Using components this way is well characterized by the decorator pattern in React. Strong candidates should also know the pitfalls of HOCs. For example, HOC-injected props may conflict with preexisting component props, and too much HOC nesting can reduce codebase readability. Your candidate should be able to suggest React hooks as an alternative way to share stateful logic without increasing the complexity of the component hierarchy like HOCs do.
Describe the concurrent features available since React v18.0 and how you would use one of them.
React’s concurrent features allow for interruptible rendering and handle it in a user-friendly way. They do this by rendering in the background instead of blocking the main thread and keeping DOM mutations until a render is complete. React v18.0 and later versions let you mark an update as either urgent (the previous default, now intended only for reflecting direct user interaction like typing) or transitionary (for less immediate updates, such as fetching autofill results). Candidates should also know how to do the latter within a component via the useTransition hook and the startTransition function it returns, and that there’s a stand-alone startTransition available for use outside of components.
What does React’s automatic batching do, and how is it enabled?
When using the ReactDOM.render method directly, React will try to reduce rerendering by grouping updates, but it can only batch those that occur within React event handlers. Automatic batching goes a step further by including asynchronous updates, such as those occurring in promises, native event handlers, and functions passed to setTimeout. To enable automatic batching, a developer has to create a root with ReactDOMClient.createRoot and only then call the render method of the returned root object (instead of ReactDOM).
What is JSX? How does it work, and why would you use it?
JSX is an XML-like syntax that simplifies the code when creating components. However, JSX is JavaScript, not XML; React transforms the JSX syntax into pure JavaScript. In many cases, JSX makes the code easier to understand, especially for those familiar with HTML and XML. Being able to decipher JSX syntax is an essential skill for a candidate because they might be tasked with debugging or maintaining code that uses it.
Why Do Companies Hire React.js Developers?
React is currently the leading front-end toolkit for building web applications and high-end solutions, and is also a crucial part of the development process for many mobile applications thanks to React Native. Seeking ReactJS development services is an excellent choice for new projects, and existing projects are likely to be using React already.
React is particularly noted for building reusable components that allow developers to standardize UI appearances and functionalities across projects. Focusing on code reusability leads to increases in development speed and code quality, as well as more easily maintainable code. Because of its popularity, React has broad developer community support from millions of programmers worldwide and has many compatible toolkits and supporting libraries available for specialized functions. React is also known for the flexibility and convenience of its virtual DOM model and its exceptionally fast UI rendering. Because React can be used for both web and mobile applications (including both iOS and Android), the same codebase can be used across multiple platforms.
In all cases, an engineer’s quality of work directly impacts the UX of a company’s end product, so it’s essential to hire ReactJS developers whose strengths are sufficient to stand alone or complement an existing development team, depending on your project resources. Using the job description and interview question advice in this guide, you now have the background to define and advertise your business requirements, attract and vet a React developer of the appropriate caliber, and, finally, find the perfect match needed for your project’s success.