Introduction
As web applications grow in size and complexity, so do the challenges of building, maintaining, and scaling them. In the world of backend development, microservices have long been the go-to architecture for breaking down monolithic systems into manageable components. But what about the frontend?
Enter micro frontends—a modular approach to frontend architecture that brings the scalability, autonomy, and agility of microservices to the UI layer.
In this guide, we’ll explore what micro frontends are, how they work, and why they’re becoming a powerful solution for building scalable, flexible web applications in large development teams and enterprise environments.
What Are Micro Frontends?
Micro frontends is an architectural style where a web application is divided into smaller, independently deliverable frontend components, each owned by different teams and potentially built using different technologies.
Just like microservices in the backend, each micro frontend (MFE) handles a distinct feature or business domain and can be developed, tested, and deployed independently.
Core Principles:
- Decentralised ownership
- Independent deployment
- Tech-agnostic architecture
- Isolated development and testing
- Composition at runtime or build time
How Micro Frontends Work
There are multiple ways to implement micro frontends depending on project needs, including:
1. Server-Side Composition
- Different frontend parts are assembled on the server before being delivered to the client.
- Good for initial performance but may reduce runtime flexibility.
2. Client-Side Composition
- Independent apps (or “fragments”) are loaded and rendered dynamically in the browser.
- Requires more JavaScript but allows highly dynamic integration.
3. Build-Time Integration
- Separate teams build their parts, which are then combined during the build process into one deployable app.
- Simpler than runtime integration but less flexible post-deployment.
4. iFrames (Old but sometimes valid)
- Offers isolation but lacks seamless communication and shared styling.
Common Tools and Frameworks:
- Module Federation (Webpack 5)
- Single-SPA
- Bit.dev
- Qiankun (for micro frontends in China)
Benefits of Micro Frontends
✅ Scalability Across Teams
Different teams can build and deploy parts of the frontend independently—ideal for large organisations or distributed teams.
✅ Tech Stack Flexibility
Each team can choose their own framework (React, Angular, Vue, etc.)—useful during gradual migrations or experiments with new tech.
✅ Independent Deployment
Micro frontends can be released separately, reducing bottlenecks and enabling faster delivery cycles.
✅ Better Code Isolation
Each feature or module has its own codebase, leading to fewer merge conflicts, cleaner boundaries, and improved maintainability.
✅ Domain-Driven Design (DDD) on the Frontend
Teams can own an entire business domain end-to-end—from backend services to frontend UI.
Ideal Use Cases for Micro Frontends
- Large enterprise apps with multiple development teams
- Apps requiring frequent updates to individual sections
- Gradual migration of legacy systems to modern frameworks
- Companies with multiple product teams sharing one UI platform
- Multi-tenant apps with highly customised frontend components
Real-World Example:
A retail company may have separate micro frontends for product listing, shopping cart, checkout, and user profile—all developed and deployed independently.
Challenges of Micro Frontends
While powerful, micro frontends come with trade-offs:
⚠️ Increased Complexity
- Requires orchestration of routing, shared state, and authentication.
- Coordination between teams is crucial despite autonomy.
⚠️ Performance Overhead
- Risk of duplicate dependencies or larger initial loads if not optimised properly.
⚠️ Shared Styles & UX Consistency
- Without design system enforcement, apps may feel inconsistent.
⚠️ Versioning and Communication
- Managing versions of shared components (like headers or footers) can get tricky.
Best Practices for Micro Frontend Architecture
1. Use a Shared Design System
Establish and enforce a consistent design language across all MFEs.
2. Lazy Load Fragments
Load parts only when needed to improve performance and reduce bloat.
3. Avoid Shared State Where Possible
Let each MFE manage its own local state to maintain independence.
4. Use Webpack Module Federation
Enable seamless runtime composition of MFEs with shared dependencies.
5. Set Clear Ownership
Define team responsibilities and boundaries around domains and components.
6. Automate Integration Testing
Test micro frontends both independently and as part of the whole app to ensure reliability.
Conclusion
Micro frontends offer a modern solution to scaling frontend development in complex, team-heavy environments. By breaking down the UI into modular, maintainable parts, organisations can build faster, innovate independently, and adapt to change without breaking the entire application.
While not a fit for every project, micro frontends shine in large, complex apps where agility and autonomy are essential.
Thinking of scaling your frontend architecture?
Explore how micro frontends can bring flexibility, speed, and structure to your development process.
