# Frontend Performance Optimization Guide

## Quick Performance Solutions

### 1. For Immediate Speed Improvement (Recommended)

**Build and run the production version:**
```bash
npm run performance
```
This builds the optimized production version and runs it on port 3001, which will be significantly faster than the development server.

### 2. For Development Speed

**Use the fast development mode:**
```bash
npm run dev:fast
```
This runs the development server with optimized settings on port 3001.

## Port Configuration

- **Backend API**: Port 3000 (default)
- **Frontend Development**: Port 3000 (default) or 3001 (fast mode)
- **Frontend Production**: Port 3001

## Performance Strategies

### Development vs Production Performance

| Mode | Speed | Port | Features | Use Case |
|------|-------|------|----------|----------|
| `npm run dev` | Slow | 3000 | Hot reload, debugging | Development |
| `npm run dev:fast` | Medium | 3001 | Hot reload, optimized | Development |
| `npm run performance` | Fast | 3001 | Optimized, no hot reload | Testing/Production |

### Why Development Mode is Slower

Development mode includes:
- Hot module replacement (HMR)
- Source maps
- Unminified code
- Development warnings
- Type checking
- ESLint checking

### Production Mode Benefits

Production mode provides:
- Minified and optimized code
- Tree shaking
- Code splitting
- Optimized images
- Faster rendering
- Smaller bundle sizes

## Performance Optimization Techniques

### 1. Code Splitting

The Next.js config now includes automatic code splitting:
- Vendor chunks are separated
- Dynamic imports for large components
- Route-based splitting

### 2. Bundle Optimization

- **SWC Minification**: Faster than Terser
- **Package Optimization**: Optimized imports for UI libraries
- **Tree Shaking**: Removes unused code

### 3. Image Optimization

- **WebP/AVIF formats**: Smaller file sizes
- **Responsive images**: Automatic sizing
- **Lazy loading**: Images load when needed

### 4. Caching Strategies

- **Static generation**: Pre-built pages
- **Incremental Static Regeneration**: Fresh content with caching
- **CDN optimization**: Distributed content delivery

## Performance Monitoring

### Analyze Bundle Size

```bash
npm run build:analyze
```

This will show you:
- Bundle size breakdown
- Largest dependencies
- Optimization opportunities

### Type Checking

```bash
npm run type-check
```

Ensures TypeScript types are correct without running the full dev server.

## Advanced Optimizations

### 1. Component-Level Optimizations

```tsx
// Use React.memo for expensive components
const ExpensiveComponent = React.memo(({ data }) => {
  return <div>{/* expensive rendering */}</div>
});

// Use useMemo for expensive calculations
const expensiveValue = useMemo(() => {
  return expensiveCalculation(data);
}, [data]);

// Use useCallback for event handlers
const handleClick = useCallback(() => {
  // handle click
}, []);
```

### 2. Lazy Loading

```tsx
// Lazy load components
const LazyComponent = dynamic(() => import('./LazyComponent'), {
  loading: () => <div>Loading...</div>
});
```

### 3. Virtual Scrolling

For large lists, consider virtual scrolling libraries:
- `react-window`
- `react-virtualized`

## Environment-Specific Optimizations

### Development Environment

1. **Use Turbopack**: Already enabled in your config
2. **Disable unnecessary features**: Remove console logs in production
3. **Optimize imports**: Use the `optimizePackageImports` config

### Production Environment

1. **Enable compression**: Gzip/Brotli compression
2. **Use CDN**: Serve static assets from CDN
3. **Enable caching**: Browser and server-side caching
4. **Monitor performance**: Use tools like Lighthouse

## Troubleshooting Slow Performance

### Common Issues

1. **Large bundle size**: Use bundle analyzer
2. **Unnecessary re-renders**: Use React DevTools Profiler
3. **Slow API calls**: Implement caching and loading states
4. **Heavy third-party libraries**: Consider alternatives or lazy loading

### Performance Checklist

- [ ] Use production build for testing
- [ ] Implement code splitting
- [ ] Optimize images
- [ ] Minimize bundle size
- [ ] Use React.memo where appropriate
- [ ] Implement proper caching
- [ ] Monitor Core Web Vitals

## Recommended Workflow

1. **Development**: Use `npm run dev:fast` for faster development
2. **Testing**: Use `npm run performance` to test production-like performance
3. **Production**: Use `npm run build && npm run start` for deployment

## Performance Metrics to Monitor

- **First Contentful Paint (FCP)**: < 1.8s
- **Largest Contentful Paint (LCP)**: < 2.5s
- **First Input Delay (FID)**: < 100ms
- **Cumulative Layout Shift (CLS)**: < 0.1

## Tools for Performance Analysis

- **Lighthouse**: Built into Chrome DevTools
- **WebPageTest**: Detailed performance analysis
- **React DevTools Profiler**: Component-level performance
- **Bundle Analyzer**: Bundle size analysis