Everything you should know about building a dynamic MERN application for the web, from architecture and components to the stack’s pros and cons.

Lifehacks 

Yevheniy Kladov

May 1, 2024

Building Dynamic Web Applications with MERN: Your Comprehensive Guide

The MERN stack is worth your consideration if you’re looking to build a data-driven, dynamic web app. Let’s break down the ins and outs of the MERN stack web development, from how a MERN application works and its components to the pros and cons of the stack and when to choose it.

What Is MERN Web Development?

MERN stack web development means using MongoDB, Express, React, and NodeJS to build web applications that have to be scalable, dynamic, and data-heavy. We’ll break down each of these technologies and their roles below.

As for how to deploy MERN stack application, the process isn’t inherently different from other stacks. You can choose from three deployment options:

  • Keeping the client-side (React) and server-side (Express) code on the same machine
  • Storing the API behind a proxy, which means Express and React code will remain on the same machine but will be served by different servers
  • Storing the Express API and React code on different machines

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How a MERN Application Works

Like any other web app, a MERN application consists of three key components:

  • Presentation layer (UI/frontend). This is the interface that users see and interact with. In full-stack MERN development, it’s built with React, a JavaScript library developed and maintained by Meta.
  • Application layer (backend). This is the business logic processing and runtime component. In MERN apps, the application logic is written using Express, a JavaScript framework, and executed in the Node.js runtime.
  • Database layer. It stores all the data that the backend may require and supplies it in response to HTTP requests. In MERN apps, it’s powered by MongoDB, a NoSQL database program.

How to Develop a MERN Application in 7 Steps

In broad strokes, MERN stack web development involves:

  • Creating the presentation layer with React: building the UI based on wireframes and prototypes
  • Creating the database layer with MongoDB: creating a project with a new database cluster and connecting it to the application
  • Setting up the server with Express and Node.js: installing dependencies (express, mongoose, dotenv), creating schema models
  • Building the application logic in the server file(s)
  • Building RESTful APIs to handle requests via routes
  • Connecting the client-side code to the server-side code
  • Deploying the application to the hosting environment

4 MERN Stack Components

Let’s take a closer look at the four technologies that comprise a MERN stack application:

  • MongoDB. It allows for storing JSON data natively, and its query language is built on JavaScript. Its strengths include seamless integration with Node.js, flexible document schemas, high performance and speed, and native support for distributed databases.
  • Express. This lightweight JavaScript framework serves as the de facto standard for the Node.js runtime environment. Express allows for building RESTful APIs and web applications with faster I/O and requests/responses.
  • React. This JavaScript library enables building a fast and dynamic UI for a MERN application. React allows for component reusability and re-rendering limited to changed DOM elements.
  • Node.js. Built on the V8 JavaScript engine, this JavaScript runtime environment enables code execution outside the user’s browser. Its strengths include high performance for real-time applications, easy scalability, and quick caching for faster loading times.

MERN Development Pros & Cons

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Pros

  • Same underlying programming language. MERN technologies are all based on JavaScript. So, the code and data don’t need to be converted during the interactions between app layers. This improves performance and facilitates component reuse and debugging.
  • High scalability and performance. All the MERN technologies come with these two strengths. Ergo, your whole application, from the database to the user interface, can handle complex interactions and advanced logic more easily.
  • Increased development productivity. MERN technologies all allow for faster development. For example, React enables component-based front-end development.
  • Real-time web app capabilities. Node.js is designed to power real-time apps with its event-driven nature.

Cons

  • Expertise still required. While it’s easier for a JavaScript-savvy developer to get started with MERN, they still need to know their way around each technology’s strengths and weaknesses.
  • Potential bottlenecks. Using JavaScript for both the server and client code may lead to performance bottlenecks – unless developers properly optimize the code, that is.
  • Potential SEO challenges. This is the bane of all dynamically generated user interfaces: their contents may remain uncrawled, leaving single-page MERN applications unindexed.
  • No built-in authentication capabilities. You’ll need to rely on third-party tools to implement user authorization and authentication features – those aren’t natively supported by MERN technologies.

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When to Opt for MERN Development: 4 Use Cases

While MERN can be used for building virtually any type of web app, it truly shines in the following use cases:

  • Real-time collaboration tools (e.g., project management tools, calendars)
  • Social media platforms, messengers, and forums
  • Fintech web applications (e.g., online banking portals)
  • Aggregators (e.g., flight aggregators, news aggregators)

MERN is the best stack for your web application if it’s going to handle large amounts of data and involve a lot of interactive features.

Want to learn more about web app design and development? Make sure to check out Fivecube's blog for our first-hand insights!

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Simple MERN App Request/Response Example

Imagine you’re a customer who wants to update their phone number on a MERN-powered online store. You head to the corresponding page (built with React) and fill out the form. Here’s what happens next:

  • The React UI sends the HTTP request to the Express code, along with the new phone number as a parameter.
  • Express code takes the parameter, maps it to the data model scheme, and updates the value in the database using the corresponding method.
  • The database returns a success or failure response, which then triggers a corresponding message in the UI.

What to Consider During MERN Web Development

While MERN is a suitable choice for virtually any type of web app, keep these two things in mind when opting for this stack:

  • Code optimization. Using the same language for the whole application may lead to bottlenecks. To avoid performance issues, the web app code that involves intensive computations has to be optimized for performance.
  • Browser support. MERN apps come with limited support for older browsers since those typically aren’t fully compatible with the latest JavaScript capabilities. If older browser support is a must, developers should pay close attention to potential compatibility issues.

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In Conclusion

MERN is the stack of choice for building lightning-fast dynamic web apps with complex application logic and advanced interactive features. Thanks to its reliance on JavaScript, MERN powers web apps with high performance and scalability – provided the development team optimizes the code accordingly, of course.

Considering MERN for your web app? We at Fivecube can help you turn your idea into a powerful MERN web app. Get in touch with us to discuss how our MERN development skills can serve your business.

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