Hiring A ReactJS Developer? Consider These Things First

One of the most popular open-source JavaScript libraries is called ReactJS. It’s a large front-end library developed by Facebook in 2011 to control the view layer (user interface) for websites and mobile apps. It is a strong contender for web and app developers to benefit from when they want to produce quality app products.

ReactJS has a set of unique features that speeds up front-end development tremendously. The advantages are many, such as more transparent development, lower development costs and of course quicker-to-market launch date.

Some of the most successful companies today are using ReactJS for their apps, including Facebook (naturally), Shopify, Coinbase, Tesla, Pinterest, and Uber Eats.

First, we’ll go over the advantages of working with ReactJS for development, then we’ll go into details about what you should look for in a ReactJS developer, the skills they should possess, and a quick summary of what they entail, so you can analyze their answers and make a decision based on that.

The advantages of using ReactJS for development:

ReactJS is the most used framework in 2021 with over 40% of developers choosing that as their preferred tool. The remaining 60% of software developers are spread across using 17 different competitor frameworks, such as JQuery, Angular, and ASP.NET Core.

The 5 most distinguished features of ReactJS are:

• One-way data flow: ReactJS has unidirectional data flow, making it impossible to edit any component directly. Instead, developers have to pass a state to the view and child components, actions are then initiated from view and updating the state.
• JavaScript XML (JSX): allows the usage of including HTML looking syntaxes in ReactJS. It makes it a lot easier for developers to control the look and feel of an app’s user interface.
• The Virtual DOM: ReactJS’ Virtual DOM is a JavaScript object which works as a copy of the physical DOM. Most efficient within virtual DOMs is that ReactJS only updates the area of the page affected instead of constantly redrawing all the components. For example, if you have a list of 20 items and make edits to 1 of the items, most JavaScript frameworks would rebuild all 20 items. ReactJS only rebuilds the affected item, a remarkable time-saver.
• Fast performance: One of the core goals for React is unparalleled performance delivery. Unlike competing frameworks AngularJS and jQuery it uses one-way data flow, and that makes for fast web and mobile apps that excel by only updating necessary properties delivering an overall faster user experience.
• Optimal SEO results: Since ReactJS is hosted on a server and functions like any other website with HTML/CSS/JavaScript or similar technology, there is no need to implement any SEO hacks unlike the other frameworks available.

What to look for when hiring a ReactJS developer

When you are looking to hire a ReactJS developer, make sure he/she has knowledge and experience with the topics below when it comes to building web or mobile apps.

A comprehensive understanding of JavaScript

JavaScript is part of React, so it’s essential that developers understand JavaScript syntax, features, and operations. It is also helpful for developers to understand the concepts of data-driven design and how to implement them.

Too often developers have shown to be good at coding, but not at designing (and rightfully so). Developers should however have a basic understanding of UI design.

A good ReactJS developer should also understand DOM manipulation, hoisting, functions, and even bubbling.

A good comprehension of how to do quality testing on their code

Knowing how to test the code for any bugs during development is essential for any good ReactJS developer, in order to mitigate any risk factors immediately and not end up with unstable apps that will require extensive re-coding or in the worst case a complete rebuild.

The most popular tools for quality assurance that you should ask if your developer knows some or all of are listed below.

For Unit Testing in ReactJS Development

• Jest – this is Facebook’s preferred testing framework to test components. Jest works with popular JavaScript projects such as Vue, NG, and Babel.
• Mocha – another great JavaScript testing framework with asynchronous testing, browser support, and test reports. It is highly customizable and can be adjusted by the developer to decide on which approach to take when testing the code. It can even work in pairs with other testing tools such as Enzyme and Chair, to do mock-ups, etc.
• Chai – A powerful BDD / TDD assertion style library to use with browser and node. Similar to the two tools above, Chai can be paired with other JavaScript testing frameworks. Popular pairing frameworks include Mocha with Enzyme and Jest.
• Jasmine – is best described as a BDD-based JavaScript testing framework for node.js and browsers. It has no dependence on other JavaScript frameworks, browsers, or DOM. It has support for running automated tests for synchronous and asynchronous programming.
• Enzyme – this tool is not a testing framework, but a useful tool in combination with some of the testing frameworks above. A popular combination is using Jest and Enzyme in tandem to test your mobile app or website. An enzyme can render components for a live preview and display elements for interaction testing.

For Integration testing in ReactJS Development

• Karma – Karma can execute JavaScript code in a browser environment and is used as a robust extension by Jasmine, Mocha, and more.

For end-to-end testing in ReactJS Development

• Selenium WebDriver – When you are going to do end-to-end testing, Selenium should not be overlooked. It’s one of the most widely used tools for automation testing and a functional cross-platform testing tool, complete with predefined interactions void of any human input.
• Cypress – this testing tool is a viable alternative to the popular Selenium. Contrary to Selenium, it is not dependent on any driver binaries to run on a real browser. It is easily configured in an intuitive dashboard and in addition to the great testing capabilities, it also has a quite neat reporting tool.
• Puppeteer – Using headless browser technology, Puppeteer provides automated control of a web browser without providing a user interface. Instead, the tester must use a command-line interface making this less intuitive than its competitors. Developed by Google, it only works in their Chrome browser where the tester can enter JavaScript commands to perform certain actions.

Does the developer know how to work with Version Control Systems (VCS)?

It doesn’t matter whether you work with web or app development projects, version control is unavoidable for any project with more than one developer staffed, which frankly most projects are unless they are an indie production.

With multiple developers making changes to the code, it’s necessary that version control software helps manage the files, so they are locked whenever a developer is working on it. Version control also provides roll-back points, similar to a time machine, so if it becomes necessary to go back to an earlier date, VCS provides this option.

VCS additionally enables developers to review old code and make comparisons between old and new code. That also makes it possible to revert any changes that worked previously, while pinpointing the exact spot needing to be fixed.

A ReactJS developer should be well-versed in using VCS tools such SVN, TFS and the very popular Git. Git gives developers their own repository where they can manage the development using push, pull, add, and commit commands.

Both SVN and TFS are using centralized source control, whereas Git is distributed. TFS has the best integration into Visual Studio and in addition to source control, also provides issue tracking, reporting, virtual labs for testing, and document management.

Knowledge of related ReactJS Development technologies

A good front-end developer should know about other technologies used by ReactJS. For example, webpack is used to transform JSX code into code that browsers can read. Similarly, Babel is used to transforming the ES6 JavaScript syntax into ES5, and ReactRouter and Redux are important open source tools to help build complex apps.

Experience with backend technologies like Ruby on Rails or Django is also a plus, so they understand how to combine the technologies in the best possible way.

Final thoughts

ReactJS is a great framework and the best among JavaScript frameworks, the ability to take full advantage of all its features though depends entirely on the skills of your ReactJS developer.

Comprehensive experience with JavaScript is a must, and mastering the tools that enhance the entire development process is key to a great developer as well.