# Lessons from Building Micro Frontend Architecture at Scale
When we started scaling our front-end development across 8 independent teams at Shiba Inu, we quickly realized that our monolithic approach wasn't going to work. Teams were stepping on each other's toes, deployments were becoming increasingly risky, and our development velocity was slowing down despite having more engineers.
This is the story of how we implemented a micro frontend architecture that not only solved these problems but actually improved our development speed by 60%.
## The Problem: Growing Pains
Our main application had grown to over 200 components, 50+ pages, and was being worked on by 8 different teams. The symptoms were clear:
- **Deployment conflicts**: Teams couldn't deploy independently
- **Slow builds**: Full application builds were taking 15+ minutes
- **Code conflicts**: Merge conflicts were becoming daily occurrences
- **Knowledge silos**: Teams were afraid to touch code outside their domain
## The Solution: Micro Frontend Architecture
After evaluating several approaches, we decided on a Module Federation-based micro frontend architecture. Here's what we built:
### 1. Shell Application
A lightweight shell that handles:
- Routing between micro frontends
- Shared authentication state
- Common layout components
- Error boundaries
### 2. Independent Micro Frontends
Each team owns their micro frontend with:
- Independent deployment pipeline
- Own technology choices (within reason)
- Isolated testing and development
### 3. Shared Design System
A centralized component library that ensures:
- Consistent user experience
- Shared business logic
- Common styling patterns
## Key Lessons Learned
### 1. Start with Clear Boundaries
The most critical decision was defining clear domain boundaries. We spent 2 weeks mapping out our application domains and establishing ownership:
- **Authentication & User Management** - Platform team
- **Trading Interface** - Trading team
- **Portfolio Management** - Portfolio team
- **Analytics Dashboard** - Analytics team
### 2. Shared Dependencies Are Critical
We learned the hard way that managing shared dependencies is crucial. Our approach:
```javascript
// webpack.config.js
module.exports = {
plugins: [
new ModuleFederationPlugin({
shared: {
react: { singleton: true },
'react-dom': { singleton: true },
'@company/design-system': { singleton: true }
}
})
]
}
```
### 3. Communication Patterns Matter
We established several communication patterns:
- **Event Bus**: For loose coupling between micro frontends
- **Shared State**: For critical application state (user, auth)
- **URL-based**: For navigation and deep linking
### 4. Testing Strategy Evolution
Our testing approach had to evolve:
- **Unit tests**: Each micro frontend maintains its own
- **Integration tests**: Shell application tests micro frontend integration
- **E2E tests**: Comprehensive user journey testing
## The Results
After 6 months of implementation:
- **60% faster development velocity**
- **90% reduction in deployment conflicts**
- **45% faster build times**
- **Zero cross-team blocking issues**
## Common Pitfalls to Avoid
### 1. Over-Engineering Early
Don't start with micro frontends. We only moved to this architecture when we had clear pain points and team boundaries.
### 2. Ignoring Performance
Micro frontends can impact performance if not implemented carefully. We use:
- Lazy loading for non-critical micro frontends
- Shared dependency optimization
- Bundle analysis and monitoring
### 3. Inconsistent User Experience
Without proper governance, micro frontends can lead to inconsistent UX. Our design system and UX review process prevents this.
## Conclusion
Micro frontend architecture isn't a silver bullet, but when implemented thoughtfully, it can solve real scaling problems. The key is understanding your specific pain points and designing a solution that addresses them without over-engineering.
If you're considering micro frontends, start by clearly defining your team boundaries and communication patterns. The technical implementation is often the easier part.
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*Have questions about micro frontend architecture? Feel free to reach out on [LinkedIn](https://linkedin.com/in/lerdafelipe) or [email me](mailto:lerdafelipe@gmail.com).*