Building Micro-Frontend Architectures with React and Next.js

Published: 20 June 2024

Introduction

The demand for modular, scalable, and maintainable front-end architectures has led to the rise of micro-frontends. Micro-frontends allow teams to independently develop, deploy, and maintain individual parts of a web application, while still presenting a unified experience to the end-user.

In this post, we’ll explore how to build a micro-frontend architecture using React and Next.js. We’ll break down the approach, share the latest techniques, and explore how to build modular, scalable, and maintainable applications for large and distributed systems.

What Are Micro-Frontends?

Micro-frontends extend the concept of microservices to the front-end. Instead of having one monolithic front-end application, a micro-frontend architecture divides the user interface into smaller, independent “micro-apps” or “modules.” These micro-apps are usually responsible for distinct pieces of functionality (e.g., a user profile, shopping cart, or payment system).

The key benefits of a micro-frontend architecture include:

Independent Deployment: Teams can deploy features independently, without worrying about breaking the entire app.
Separation of Concerns: Each team is responsible for a specific part of the application, improving maintainability.
Scalability: Micro-frontends can scale independently based on their usage or complexity.
Technology Agnostic: Teams can choose the best tools or frameworks for their specific module, though it’s still common to use the same tech stack (e.g., React, Next.js) for consistency.

Building Micro-Frontends with React and Next.js

Next.js and React provide a powerful foundation for building scalable, performant micro-frontends. Let’s dive into the steps of building a micro-frontend architecture.

1. Setting Up a Micro-Frontend Architecture

The first step is to divide your app into separate, independently deployable modules. In a typical Next.js-based project, we might want to separate sections like the header, sidebar, user dashboard, and product listing into independent React components or even entire pages.

There are several strategies for implementing micro-frontends:

Single SPA (Single Page Application): A popular framework that allows you to load multiple micro-frontends (or applications) into a single web page, each potentially built with a different framework or version.
Module Federation (Webpack 5): A Webpack feature that allows different parts of your app to share code dynamically at runtime.

However, Next.js provides a more straightforward approach using dynamic imports, micro-apps, and custom routing.

2. Dynamic Import for Micro-Frontend Modules

To implement a modular system, we can use Next.js’s dynamic import feature to load components only when they are needed. This helps with performance and ensures that only the relevant micro-frontends are loaded on demand.

For example, let’s say you have a micro-frontend for the Product List in your app. You could dynamically import it as follows:

// pages/index.js
import dynamic from 'next/dynamic';

const ProductList = dynamic(() => import('../components/ProductList'), {
  ssr: false, // Optionally disable SSR if it's not required for this component
});

export default function HomePage() {
  return (
    <div>
      <h1>Welcome to our Store</h1>
      <ProductList />
    </div>
  );
}

By using dynamic imports, only the necessary micro-frontend for product listing is loaded when needed, optimizing your app’s performance.

3. Independent Routing for Micro-Frontends

For large applications, you might want different micro-frontends to handle different parts of the app’s URL structure. Next.js allows you to handle routes and map them to micro-frontends.

In a micro-frontend approach, each module might have its own route or path. This can be achieved by configuring custom routing and React Router.

For example:

// pages/products/[id].js
import dynamic from 'next/dynamic';

const ProductDetails = dynamic(() => import('../../components/ProductDetails'), {
  ssr: false,
});

export default function ProductDetailsPage({ id }) {
  return (
    <div>
      <ProductDetails productId={id} />
    </div>
  );
}

This structure allows independent development, testing, and deployment of the ProductDetails micro-frontend, which is accessible at /products/:id.

Next.js also supports API routes, so you can create isolated backend functionality for each micro-frontend that handles its specific needs. These routes can be used to fetch product data, handle payment processing, or interact with a backend system, independent of other micro-frontends.

4. Sharing State Between Micro-Frontends

One of the challenges with micro-frontends is managing shared state across independently deployed modules. In a traditional monolithic app, state management is easier because everything lives in the same context. However, in micro-frontends, we need to be mindful of how the state is shared.

There are several strategies to handle shared state in a micro-frontend architecture:

React Context: A great option for sharing state between micro-frontends in a simple app. If you have a small-scale system where the micro-frontends are closely related, you can use React Context to pass data across components. Example of using React Context:

  // context/GlobalState.js
  import { createContext, useContext, useState } from 'react';

  const GlobalStateContext = createContext();

  export function GlobalStateProvider({ children }) {
    const [user, setUser] = useState(null);

    return (
      <GlobalStateContext.Provider value={{ user, setUser }}>
        {children}
      </GlobalStateContext.Provider>
    );
  }

  export function useGlobalState() {
    return useContext(GlobalStateContext);
  }

You can wrap the entire application with the GlobalStateProvider, and all micro-frontends can access and update the state.

Custom Event Emitters: If your micro-frontends are relatively isolated or use different frameworks, you can use custom events or a pub/sub system to communicate between modules.
External State Management (Redux, Zustand, or Recoil): For larger-scale applications, using a state management library like Redux, Zustand, or Recoil can help synchronize state across micro-frontends more efficiently.

5. Deployment and CI/CD for Micro-Frontends

Once your micro-frontends are developed, the next challenge is deployment. Each micro-frontend should be deployable independently. Here’s how to handle deployment and CI/CD pipelines:

Independent Deployments: Each micro-frontend should be built and deployed separately. This means each module has its own deployment pipeline and versioning system.
Versioning: Micro-frontends should follow a clear versioning system. This ensures that any breaking changes to one module won’t affect others.
CI/CD: Use tools like Vercel, Netlify, or GitHub Actions to automate the deployment process. You can trigger deployments based on changes to specific modules and manage multiple deployments at once.

Here’s an example of how you can set up an independent deployment pipeline using GitHub Actions:

name: Deploy Micro-Frontend

on:
  push:
    branches:
      - main
  paths:
    - 'components/**'  # Only deploy if a component is changed

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - run: npm install
      - run: npm run build
      - run: npm run deploy

This ensures that only the relevant micro-frontend gets deployed when changes are made to its codebase.

6. Performance Considerations in Micro-Frontend Architectures

Micro-frontends can increase the complexity of an application, and if not optimized properly, they can lead to performance issues. Here are some key performance considerations:

Lazy Loading: Use dynamic imports for loading micro-frontend modules only when they are needed.
Shared Dependencies: Ensure shared libraries, such as React, are loaded only once across all micro-frontends. Tools like Webpack Module Federation or Single SPA can help avoid multiple versions of the same dependency.
Edge Computing: Leverage edge functions for fast, serverless processing of requests and data fetching at the edge. This minimizes latency and ensures fast load times for end users.
Code Splitting: Ensure each micro-frontend is independently bundled and optimized using Webpack’s code-splitting feature.

Conclusion

Building a micro-frontend architecture with React and Next.js in 2024 is a powerful approach to scaling and maintaining large web applications. By breaking down your application into smaller, independently deployable modules, you can improve developer productivity, enhance scalability, and make your applications easier to maintain.

With the right tools like dynamic imports, React Context, React Server Components, and modern deployment strategies, you can create robust and modular architectures that support complex front-end applications with minimal overhead. The flexibility and performance of Next.js combined with React make it an ideal framework for implementing micro-frontends in the modern web.