Introductio
Micro frontends are an architectural style that applies the concept of microservices to the front end. Web applications often evolve to include new features and technologies that address specific business needs. It is common for an existing application to introduce new functionality over time, and as developers, we are often required to add features that leverage new technologies.
Let’s consider a scenario where your team is building an e-commerce application with various sections, including the Homepage, Search and Browse, User Profile, Shopping cart, and Payment gateway. With the traditional monolithic architecture, all these sections would be part of a single codebase. As the application grows, managing, scaling, and deploying changes to this codebase becomes challenging. By contrast, opting for a micro frontend architecture allows these sections to be treated as self-contained modules and multiple teams to work independently on their respective modules without worrying about breaking changes in other parts of the application or waiting for or impacting other teams. Each module is responsible for a specific feature or functionality.
For example, if the payment gateway team wants to introduce a new technology to handle the transactions, it can be done without impacting the rest of the sections. Similarly, if the search and browse team decides to adopt a new technology like GraphQL or React Query, it won’t disrupt the other sections.
Micro frontends allow teams to choose their preferred tools, technology, or framework for their specific part of the application. By encapsulating functionality into smaller units, the team can work independently of each other by splitting the application into smaller, more manageable, shareable, modular components. The primary goal of a micro frontend strategy is to reduce the size of a single application to improve developer velocity while still allowing teams to collaborate.
In this blog, we will explore how a micro-frontend architecture can effectively implement React.js and Next.js applications.
A Micro Frontend Perspective
Using micro frontend principles, you can introduce Next.js features to your existing React application without disrupting the existing structure. Instead of converting the entire application, you can isolate the new feature as a separate micro frontend built using Next.js. This allows you to:
- Leverage Next.js Features : Use SSR, SSG, or dynamic routing where required, improving performance and reducing complexity for the new feature.
- Preserve React Codebase : Keep the existing React.js application intact, avoiding the need for a complete migration.
- Independent Development : Develop the new feature as an independent module, enabling faster development and deployment cycles.
- Seamless Integration : Use techniques like Webpack Module Federation, iframe embedding, or runtime integration to combine the Next.js micro frontend with the existing React application seamlessly.
Here are some common ways to implement micro frontends with React and Next.js:
1. Module Federation (Webpack 5)
Webpack’s Module Federation allows different micro frontends to dynamically load and share components or modules at runtime. Each micro frontend exposes its components or pages using Webpack’s ModuleFederationPlugin. A host application dynamically loads these exposed modules.
Benefits
- Dynamic sharing of components across applications.
- Runtime decoupling of applications, allowing independent deployments.
Next.js Consideration
- You can integrate Module Federation with Next.js, but Next.js has a custom build setup, so you need to configure Webpack in next.config.js.
2. Server-Side Composition
Compose micro frontends server-side before sending the final HTML to the client. A backend (or middleware) combines HTML fragments from different micro frontends into one unified HTML response. Each micro frontend provides an endpoint to serve its HTML fragment.
Benefits : Faster initial page load as composition happens on the server. Reduces JavaScript bundle size on the client.
Drawbacks : More complexity in the backend. Requires synchronizing APIs or contracts for HTML fragments.
Next.js Consideration : Use Next.js’s API routes or custom server for composing micro frontends server-side.
3. Client-Side Composition
Compose micro frontends dynamically in the browser. The shell app (host) fetches JavaScript bundles for micro frontends and mounts them dynamically.
Benefits : Allows independent deployment of micro frontends. No dependency on a custom backend.
Drawbacks : Slower initial load as micro frontends are fetched and composed on the client.
4. Static Composition
Compose micro frontends at build time. Shared components or pages from different micro frontends are integrated at build time. Next.js’s static generation or incremental static regeneration can be used to pre-render content.
Benefits : Ideal for static websites or parts of the app that don’t change often. Excellent performance for static pages.
Conclusion
Incorporating Next.js into a React application using a micro frontend approach enables teams to harness the strengths of both technologies. This method minimizes disruption, accelerates development, and creates a scalable and flexible architecture. By isolating the new feature as a Next.js micro frontend, you can deliver a robust solution tailored to specific business needs while maintaining the integrity of the existing application. This is the essence of a micro frontend—allowing developers to innovate and adapt quickly without being constrained by the technology choices of the past.
