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Rishabh is a software engineer having 7+ years of experience in designing front-end web applications and is expertised in web development.
Mahesh is a software engineer having 3+ years of experience in developing dynamic single page web applications and mobile apps using ReactJS and NodeJS.
Part-time React freelancer
John is a software engineer having 10+ years of experience working with Angular. He has an in-depth knowledge of Angular MVC, Unit testing framework, and RxJS.
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Want to hire freelance ReactJS developers on your own? Here are the skills you must look for while hiring a ReactJS developer
Hiring freelance ReactJS developers might be an intricate task for you if you are a non-technical manager. Today, React is one of the most demanding skills in the IT industry for developing interactive front-end, and hiring the most skilled freelance ReactJS developers among thousands of developers is challenging for anybody. So, here Ultragenius comes to assist you while recruiting the top freelance React.js developers on your own. Ultragenius understands your job requirements and gets you only the top freelance ReactJS developers who have in-depth knowledge of software development.
The following skills you must look for while hiring a freelance React developer –
- Variables and scoping
- Arrays and object
- Array methods
- Functions and arrow functions
- DOM Manipulation and event handler
- The “this” keyword
- The “class” keyword
- Prototype chain and object creation
- Higher order functions and callback functions
Well conversant with JS build tools
While working with real-world projects, React developers need to install many packages and add dependencies, file watcher, browser reloader, and many more. The developers must have the knowledge of webpack , npm, and yarn.
Excellent understanding of testing frameworks and tools
Rising quick-deployment needs during the development phase, testing has become an important skill for React developers. Therefore, the developers should know about Jest, Enzyme, Mocha, Chai, AVA, and Tape for unit testing.
For end-to-end testing, they must know about Selenium, Webdriver, Cucumber.js, Nightwatch.js, Cypress, and Puppeteer.
For integration testing, they must know about Karma.
Experienced in working with Version Control System (VCS)
Developers must have a very good knowledge of version control systems, like Git, SVN, TFS, and Mercurial. Mostly, developers use Git for their work. It is the version control system that helps the team in collaborating and organizing your code, maintain the frequent changes that occur in the code. Git helps in reviewing the old codes and compares them with the newly updated code, pulling the code from their repository, and managing the commit history.
Along with this, the developer must know how to use add, push, pull, and commit commands, branching, and merging as it allows developers to work independently on the code.
Knowledge of MVC architecture
React developers must know about Model-View-Controller (MVC) architecture. MVC approach helps you to create applications that separate the input logic, business logic, and UI logic while maintaining the loose coupling between the elements.
Experience developing RESTful API(s)
A developer must know what REST – API(s) that are used in HTTP requests using GET, PUT, POST, and DELETE methods, which enable developers to read the web application more clearly and use it effectively.
Experience with web markup and UI, UX Concepts
The developer must have a firm understanding of element positioning, displaying the elements, and making components interactive, semantic markup, and other related UX Concepts so they can design the product with the best quality. The developer must be experienced in developing visual effects in presentational markup. For, example – How the heading appears, making text larger and putting weight to it, and giving which color to it, and which markup can include captions, bind columns, and row headings to table cells.
Experience working with ReactJS workflows
Check if they have worked with the popular libraries like Redux, Mobx, and Context APIs.
Proficient in writing optimized and readable code
You must hire the developers based on their ability to write clean and optimized code that is understandable by all the team members, and is scalable.
Pay only after one week trial period
Connect with the top 1% freelance React.js developers of the world at the lowest prices
Top Interview Questions to ask while hiring a freelance React.js developer
React DOM is slow as compared to Virtual DOM. React DOM can directly update HTML while Virtual DOM doesn't directly update HTML. Real DOM creates a new DOM if the element updates while Virtual DOM updates the JSX if the element updates. Real DOM manipulation is very expensive while Virtual DOM manipulation is very easy.
The virtual DOM is a programming concept where a virtual representation of UI is kept in memory and synced with the real DOM with the help of a library like ReactDOM. This process is called "Reconciliation".
Whenever any data is changed in UI, the changes are rendered in Virtual DOM first, then Virtual DOM is compared with Real DOM, the Real DOM will be updated only with the things that have been changed.
React lets you use state and other React features without writing a class. It makes logic and UI separable easily. To change a functional component into a class component requires a little bit of refactoring, but with React hooks functional components have the capability of tapping into the state, so that the refactoring effort will be minimal.
The lifecycle of the component consists of four phases -
- Initialization - The constructor() method is called before anything else when the component is initiated and sets up the initial state and other initial values. This method is called when your component is created but is not added to the DOM. Its main use is to initialize the state and bind this for component methods.
- Mounting - The component is added to the React DOM. Mounting includes the following methods like constructor(), getDerivedStateFromProps(), render(), and componentDidMount().
- Updating - The component receives changed props or states and is called when the components is re-rendered. Updating the component includes shouldComponentUpdate (), componentWillUpdate (), componentDidUpdate () methods.
- Unmounting - The component is removed from the React DOM. It includes the method componentWillUnmount().
Far far away, behind the word
- React increases the efficiency of an app by using Virtual DOM
React uses Virtual DOM which is the virtual representation of the Real DOM, each time when the data changes in a React application, a new Virtual DOM is created instead of reloading the page every time.
- Embedded JSX Feature
- SEO-friendly User Interface
React enables developers to develop engaging user interfaces that can be easily directed in search engines. React also allows server-side rendering, which improves the SEO of an application.
- Components are reusable
For developing applications, React uses component-based architecture. Components are independent and can be shared across various applications having similar functionality. The re-use of functionality enables developers to quickly design pages.
Props stand for Properties in React. Props are the read-only components generally used to render dynamically generated data. Props are passed in the functions as similar as the arguments are passed. Props are always sent from parent to child component and never vice-versa.
- Props are immutable while the States are mutable.
- Props allow you to pass information from one component to another in the argument form, while a State doesn't pass but holds the information about the components.
- Props make a component reusable by passing it to the child component while States do not have any functionality like this.
- Props are external and are controlled by whatever renders the component while the State is internal and is controlled by the React Component itself.
- Props are used to communicate between the components, States can be used for rendering dynamic changes with the component.
Each component must have a render() method. The render method returns a single React element which is the representation of the native DOM component.
To render more than one element, they must be grouped and enclosed inside the elements.
Hire freelance Ultragenius developers based on skills
Frequently Asked Questions
Ultragenius is one of the leading platforms for hiring remote talent and connecting freelance and part-time developers with Silicon Valley businesses. We focus on finding the best talents who will perform extremely well and will be easily integrated into your teams. We filter out only the top 1% most skilled freelance developers among the 20K+ developers who have applied on our platform. Candidates have to prove their self-reported experience by giving Ultragenius’ s skill tests.
Ultragenius first tests the developer’s skill set by conducting a two and half hour hiring test. Our hiring test judges a candidate on all aspects like aptitude, case study analysis, verbal and reasoning, coding questions based on data structures and algorithms, software engineering, system design, and more. Then, there is another round for the candidates who are selected from this round called “Higher-level Assessment Skill Test”, which is a video round that deeply analyzes freelance developers’ major skills and asks questions about the projects they have worked upon.
Fill up the form which is on every hiring freelancers’ page and we will inform you once we select the top 1% freelance React.js developers matching your job requirements. After analyzing the candidates based on their resumes and two assessment tests, we provide you the feedback quickly. And if the freelancers selected by our team are fit for your job role, then we also provide the onboarding.
Ultragenius offers you only the most skilled freelance developers who are top 1% among the 20K+ freelance developers who have applied on our platform. After a rigorous selection and testing process, we sort out only the top candidates for you. You can check out Ultragenius’ s selection process for hiring freelance React developers on http://www.ultragenius.club/hire-react-freelancer.