Skip to content

Hire Remote MERN Full Stack Developers in 24 hrs

UltraGenius is a marketplace for top MERN developers, engineers, programmers, coders, architects, and consultants. Top start-ups and companies choose developers from UltraGenius platform for their critical software projects.
Hire from UltraGenius network & scale your engineering team in a matter of few days. 

Trusted By

download (1)

Hire only the top 1% among the 20K+ engineers who have applied to UltraGenius


MERN developer

Rishabh is a software engineer having 7+ years of experience in designing Single Page Applications and mobile applications using MERN stack

Expert in






10 Years


Full Time


MERN developer

Mahesh is a software engineer having 3+ years of experience in developing dynamic single page web applications and mobile apps using MERN stack.

Expert in






10 Years


Full Time


Part-time MERN developer

John is a software engineer having 10+ years of experience developing websites and applications using MongoDB, Express, Node, and React.js as the front-end library framework.

Expert in






10 Years


Full Time

MERN Stack

Hire dedicated MERN stack developers with UltraGenius

MERN stands for MongoDB, ExpressJS, ReactJS, and NodeJS and is an excellent choice for developing full-stack web applications. MERN full stack developers quickly handles front-end and back-end using high-performance React.js for the front-end which reduces the application’s load-time and Node.js on the backend handling requests asynchronously with its non-blocking I/O. MongoDB is a great choice for database in developing applications which allows MERN programmers to store and access data easily through document objects. With the help of Express.js, it becomes easier to configure and customize a web application.

What UltraGenius offers?

Fast Hiring

ultraGenius ensures that top quality developers with the most talent are hired in less than 72 hours.

Intelligent Matching

The matches are specifically curated as per your needs. We dim fit 3 skills - Tech, Culture, and Context Fit.

Rigorous Vetting

ultraGenius conducts tests and ensures that only the most suitable developer with the best skills is hired.

Hire MERN developers through UltraGenius in 4 easy steps

Tell us the skills you need

We’ll schedule a call and understand your requirements.

We find the best talent for you

Get the list of pre-vetted candidates in days.

Schedule the interviews

We will arrange a call after understanding your requirements.

Begin your trial

Start working with UltraGenius with a 1-week trial period.

Our Happy Clients

UltraGenius is the best remote talent network to meet with brilliant developers who are most talented and skilled in the technical field. UltraGenius provides the most fit developers who not only match our job requirements but also our company's culture and working environment.
Once you are part of UltraGenius, you don't have to look for another platform which can find the top skilled developers with same effort as UltraGenius. UltraGenius's vetting tests and assessments are unmatchable and provides the perfect match for the job role.
Our company is thankful to UltraGenius wholeheartedly. UltraGenius's pace of finding the top 1% developers is unmatchable. Not only UltraGenius developers are the ones who match our job requirements but also the best fit to our company's working culture .
OYO Rooms

Join 200+ Fast-scaling Start ups
and Fortune 500 Companies that have hired MERN developers

Want to hire Remote MERN developers on your own? Here are the skills you must look for while hiring a MERN engineer

Hiring MERN full stack developers might be an intricate task for you if you are a non-technical manager. Today, MERN is one of the most demanding stack for developing full-stack web applications in the IT industry. But, hiring the most skilled MERN developers among thousands of developers is challenging for anybody. So, here UltraGenius comes to assist you while recruiting the top senior MERN developers on your own. UltraGenius understands your job requirements and gets you only the top MERN full stack developers who have in-depth knowledge of MERN stack development.

The following skills you must look for while hiring a MERN stack developer – 

Familiarity with the core HTML, CSS, and Javascript

HTML (Hypertext Markup Language), CSS (Cascading Style Sheets), and Javascript are must-know fundamental technologies for a MERN stack developer. Check the developers; knowledge of HTML5 and CSS3. The MERN developer must know more than one Javascript library framework like jQuery, Bootstrap and must be specialized in working with Asynchronous Javascript and XML (AJAX). Check if the developers have worked with Leaner CSS and Syntactically Awesome Stylesheet (SASS) and have knowledge of Javascript build tools such as Grunt.js, Gulp.js, and Bower.js.

hire software developer
part time web developer remote

Javascript fundamentals + ES6

is most widely used language in developing dynamic web applications and helps a developer integrate back-end with the front-end easily. The developers must be clear with the fundamental concepts of Javascript language. ECMAScript 6 (or ES6) is the current version of ECMAScript and is widely used by developers up to a large extent. The MERN stack developers must be familiar with these ES6 skills – 

  • 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 on real world projects, MERN stack engineers must know how to use build tools or task runners. webpack, grunt, browserify, gulp, and bower are the examples of build tools. Build tools help in combining multiple files into one (bundling), removing unused code (tree shaking), converting modern ES6+ Javascript into Javascript which an older version of browser can understand (transpiling), etc.

part time web developer
hire freelance developers

Highly Experienced in Testing Framework and Tool

Web application developer with the MERN stack must know about Jest, Enzyme, Mocha, Chai and AVA for unit testing. For end-to-end testing, they need to know Selenium and Webdriver in addition to Cucumber.js or Cypress. For integration tests they should use Karma among others like Nightwatch.js or Puppeteer

Hire MERN developers with Experience of Version Control Systems (VCS)

Top MERN programmers must know about version control systems like Git, TFS, SVN and Mercurial. Git is the most commonly used one. It helps in collaborating and organizing code to maintain frequent changes that occur in the code by adding new features on feedback received from users. Along with this a developer would need to be well versed with commands such as Add, Pushing, Pulling, Committing etc., which allows them to work independently on codes while providing updates (to branches) periodically or mutually depending upon their needs/requirements at that point of time.

freelance developer

Familiarity with Styled Components

Styled Components is one of the mostly used CSS-in-JS libraries for MERN application development because of its fastest core stylesheet engine. These Javascript files allows a MERN developer to define a User Interface (UI) component and styles in a single file. Styled components removes class name bugs by providing unique class names for the styles used, thus avoiding creation of duplicate classes.

Knowledge of NodeJS and ExpressJS

The full stack MERN developers must have experience of using ExpressJS library in their application. ExpressJS makes easier for the developers to write concise code and customize an application. Express provide the HTTP methods GET, PUT, POST, DELETE, SET, etc. , methods to specify the template engine being used, location of template files, and which template is used for rendering a response. It helps creating router handler to provide routing for the application, handle validation and 404 errors which may occur in a MERN application.

node js freelancer developer
part time developer

Experience with web markup and UI, UX Concepts

The Dedicated MERN 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

State Management in React.js library framework is the biggest challenge developers face while developing scalable and robust MERN applications. Look for the developers who have worked with projects where they have managed states across multiple components and optimized application performance.

Check if they have worked with the popular libraries like Redux, Mobx, and Context APIs.

react freelance developer

Experience using Javascript XML (JSX) in the project

Javascript XML or JSX is one of the core advantage of React. JSX allows MERN developers write HTML code inside the Javascript code making application code concise and debug easier. JSX makes it easier to use high-performance UI components in a MERN application. JSX provides warning messages and some useful errors as well while building a MERN application.

Proficient using MongoDB NoSQL datababase

MongoDB is gaining popularity now-a-days because of its great alignment with front-end frameworks like React.js, Vue.js and Angular.js. It is document database that stores data in BSON (binary representation of JSON) format. MongoDB does not need pre-defined schemas and can store heterogeneous types of data. It allows MERN developers to create multiple fields in a document. MongoDB is a powerful querying tool because any document field can be indexed and provides faster data access by using internal memory for storing data. 


Pay only after one week trial period

Connect with the top 1% MERN stack developers of India at the lowest prices

MERN stands for MongoDB, ExpressJS, ReactJS, and NodeJS and is an excellent choice for developing full-stack web applications. MERN stack quickly handles front-end and back-end using high-performance React.js for the front-end which reduces the application’s load-time and Node.js on the backend handling requests asynchronously and MongoDB as the database. But, recruiting the best MERN developers who are well-conversant with these combined technologies is not an easy task when a large number of MERN developers are competing to grab the job opportunities. So, here UltraGenius comes to assist you in hiring only the top 1% MERN developers among 20000 developers who have applied on our platform.

Top Interview Questions to ask while hiring a MERN developer

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().

JSX stands for JSX stands for Javascript XML. This is a type of syntax extension which allows us to directly write HTML in React by converting HTML into React components, which helps you to easily create user interfaces for your web applications.

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.

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.

Express.js is a robust framework of Node.js designed to minimize the lines of code while developing web applications by providing powerful set of libraries and tools which makes the development process faster and increases its scalability.

Routing specifies the way a server responds to a client's request to a particular endpoint. AN endpoint is a path and any of the HTTP methods such as GET, PUT, POST, PATCH, etc. Each route possesses one or more handler functions that gets executed when the router is matched. The syntax usually used for routing is - 

app.METHOD(PATH,HANDLER), where METHOD can be any HTTP request methods like GET, PUT, POST, DELETE, SET, OPTIONS, HEAD, and CONNECT.

To work with MongoDB, the required library is mongoose. The required steps for establishing database connectivity are - 

  • Connection Pooling – Specify the number of database connections that should be maintained and saved by Node.js.
  • Create the connection to a database. Create a callback function that can be invoked whenever the “create” method is executed.
  • To retrieve and manipulate data, execute queries from the database with the help of commands such as SELECT, UPDATE, INSERT, and DELETE.
  • Close the connection and create a callback function that can be invoked whenever the “close” method is executed.

Replication in MongoDB is a mechanism of creating the copy of data on multiple servers. It increases the data durability by ensuring that the data is written on multiple machines. In MongoDB, it is achieved by using replica sets. A replica set is a group of mongod objects / instances that maintains the same set of data. There are various data bearing nodes and one arbiter node which is optional. Only one of the data bearing nodes is treated as the primary node that receives all the write operations. The primary nodes stores all the changes occurred to its data sets in the operation log (oplog).

REST API is an Application Programming Interface that uses HTTP requests to GETPUTPOSTDELETE the data over www. The developers you are hiring should be well versed with the principles of REST – 

  • Stateless – 

The client sends the requests to the server containing all the necessary data to be dealt with. The data can be a query-string parameter, a part of URI, context body, and headers also. The URI uniquely identifies the resource and the body contains the information about the requesting resource’s state.

  • Client and Server – 

REST provides a uniform interface that separates the client from the server and helps in improving the UI portability across various platforms they use. It also increases the scalability of the server components.

  • Uniform Interface

REST API ensures uniformity throughout the application by defining four interface constraints –  Resource Identification, Resource Manipulation, Self-descriptive messages, Hypermedia.

  • Layered System 

REST provides a layered system architecture that limits the component behavior thereby ensuring stability. Layered system enables load balancing and enhances scalability by providing shared caches. It also helps in increasing the application’s security because components in each layer cannot communicate with the next immediate layer.

  • Cacheable

REST allows the client to download the applets and extend them via the interface to use in their applications.

Node.js uses asynchronous callbacks which are called at the completion of a given task. Asynchronous Callbacks are specified as function arguments while invoking a function which will start executing code in the background. When the background code stops running, async callbacks call the callback function to let the developers know about task completion.

A callback hell occurs when the freelance MERN developer resolves callback which is another callback which is yet in another callback. Using comments, splitting the large functions into smaller functions, using async / wait, and using promises can help preventing callback hell to occur. 

The developers can maintain separate blocks for piles of code and avoid writing code in deep nested structures.

For achieving transaction and locking, developers use the concept of nesting the documents which are also known as embedded or sub document. MongoDB achieves locking by using reader-writer locks which provides concurrent readers the facility to access a shared collection or database. For example, when locking is made on a collection (using X mode), then its corresponding lock and the global lock should be locked in the intent exclusive IX mode.

The worker thread is a continuous parallel thread responsible for handling CPU-intensive Javascript operations by sharing SharedArrayBuffer instances or by transferring ArrayBuffer instances. Unlike cluster or child_process, worker threads can share memory. Worker threads inherit the command line flags automatically from the running process and will preload the preload scripts same as the main thread. If the preload script launches a worker thread unconditionally, every thread that is newly created or technically 'spawned' will spawn another until the application crashes.

If you are trying to hire a Mern Full Stack Developer. Here is the Mern Full Stack Developer Job Description that you can use in your hiring.

Frequently Asked Questions

UltraGenius is one of the leading platforms for hiring remote talent and connecting developer 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 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 developers’ major skills and asks questions about the projects they have worked upon.

Fill up the form which is on every hiring developers’ page and we will inform you once we select the top 1% MERN 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 developers selected by our team are fit for your job role, then we also provide the onboarding.

UltraGenius offers you only the most skilled developers who are top 1% among the 20K+ 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 MERN developers on

UltraGenius provides you the best facility to hire developers in more than 50 skills like React, Angular, Javascript, Node, Java, Python, Magento, Ruby On Rails, Golang, PHP, WordPress, .NET, Android, iOS, DevOps, Machine Learning, and many more.