Building Scalable React Applications: Lessons from Real Projects

Source: Dev.to

By Borifan Dabasa | Full Stack Developer

The Problem with “Just Start Coding”

When I built my first React app, I threw everything into components without thinking about structure. Fast forward three months, and I was drowning in prop drilling, duplicate logic, and components that did way too much.

Sound familiar?

1. Folder Structure That Scales

Here’s the structure I use for all my React projects now:

src/
├── components/
│   ├── common/          # Reusable UI components
│   ├── layout/          # Layout components
│   └── features/        # Feature‑specific components
├── hooks/               # Custom hooks
├── context/             # Context providers
├── services/            # API calls
├── utils/               # Helper functions
├── constants/           # Constants and configs
└── pages/               # Page components

Why this works: Each folder has a single responsibility. When I need to find something, I know exactly where to look.

2. Component Composition Over Complexity

I learned this the hard way. Here’s a component from my early days:

// ❌ Bad: God component doing everything
function UserDashboard() {
  const [user, setUser] = useState(null);
  const [posts, setPosts] = useState([]);
  const [loading, setLoading] = useState(true);

  // 200 lines of logic...

  return (
    {/* 300 lines of JSX */}
  );
}

Now I break it down:

// ✅ Good: Composed components
function UserDashboard() {
  return (
    {/* composed sub‑components go here */}
  );
}

Rule of thumb: If your component is over 150 lines, it’s probably doing too much.

3. Custom Hooks for Logic Reuse

Custom hooks changed my life. Instead of copying logic between components, I extract it:

// hooks/useAuth.js
export function useAuth() {
  const [user, setUser] = useState(null);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    const unsubscribe = auth.onAuthStateChanged(setUser);
    setLoading(false);
    return unsubscribe;
  }, []);

  return { user, loading };
}

// Now use it anywhere
function Profile() {
  const { user, loading } = useAuth();

  if (loading) return ;
  return {user.name};
}

I use custom hooks for:

• API calls (useFetch, useApi)
• Form handling (useForm)
• Local storage (useLocalStorage)
• Debouncing (useDebounce)

4. State Management: Keep It Simple

I see developers reaching for Redux immediately. Here’s my approach:

• Local state for component‑specific data
• Context for app‑wide data (theme, auth)
• Redux/Zustand only when Context becomes messy

For my e‑commerce project, I used Context for cart and auth. That’s it. No Redux needed.

// context/CartContext.js
export function CartProvider({ children }) {
  const [cart, setCart] = useState([]);

  const addToCart = (item) => {
    setCart([...cart, item]);
  };

  return (
    {/* provide cart context to children */}
    {children}
  );
}

5. Performance Optimization

Code Splitting

// Lazy load heavy components
const Dashboard = lazy(() => import('./pages/Dashboard'));

function App() {
  return (
    {/* render routes with Dashboard */}
  );
}

Memoization

// Prevent unnecessary re‑renders
const ExpensiveComponent = memo(({ data }) => {
  return {/* Heavy computation */};
});

Virtual Lists

For my crypto tracker with 1,000+ coins, I use react-window:

import { FixedSizeList } from 'react-window';

{/* render CoinRow inside FixedSizeList */}

6. Error Boundaries

This saved me during production bugs:

class ErrorBoundary extends Component {
  state = { hasError: false };

  static getDerivedStateFromError(error) {
    return { hasError: true };
  }

  render() {
    if (this.state.hasError) {
      return ;
    }
    return this.props.children;
  }
}

// Wrap your app
<ErrorBoundary>
  <App />
</ErrorBoundary>

7. Environment Variables

Never hardcode API URLs:

# .env
REACT_APP_API_URL=https://api.example.com
REACT_APP_API_KEY=your_key_here

// Use in code
const API_URL = process.env.REACT_APP_API_URL;

Real‑World Example: My Blog Project

In my Next.js blog (live at ), I implemented:

• File‑based routing for automatic code splitting
• ISR (Incremental Static Regeneration) for fast loads
• TypeScript for type safety

# Tailwind CSS for consistent styling  

**Result?** Lighthouse score of **95+** and sub‑second load times.

Key Takeaways

• Structure matters – Organize by feature, not file type
• Compose, don’t complicate – Small, focused components
• Extract logic – Custom hooks are your friend
• Optimize smartly – Measure before optimizing
• Plan for errors – Error boundaries save production

What’s Next?

I’m currently exploring:

• Server Components in Next.js 14
• React Query for better data fetching
• Micro‑frontends for large apps

Want to see these patterns in action? Check out my projects on GitHub.

Questions?

Drop a comment or reach out at .

Connect with me

• GitHub: @Borifan02
• LinkedIn: Borifan Dabasa

Tags: #WebDevelopment #JavaScript #Frontend #MERN