# Feature Building
> How to analyze and implement new features.
## Feature Analysis
```
Request: "add payment system"
Analysis:
├── Required Changes:
│ ├── Database: orders, payments tables
│ ├── Backend: /api/checkout, /api/webhooks/stripe
│ ├── Frontend: CheckoutForm, PaymentSuccess
│ └── Config: Stripe API keys
│
├── Dependencies:
│ ├── stripe package
│ └── Existing user authentication
│
└── Estimated Time: 15-20 minutes
```
## Iterative Enhancement Process
```
1. Analyze existing project
2. Create change plan
3. Present plan to user
4. Get approval
5. Apply changes
6. Test
7. Show preview
```
## Error Handling
| Error Type | Solution Strategy |
|------------|-------------------|
| TypeScript Error | Fix type, add missing import |
| Missing Dependency | Run npm install |
| Port Conflict | Suggest alternative port |
| Database Error | Check migration, validate connection |
## Recovery Strategy
```
1. Detect error
2. Try automatic fix
3. If failed, report to user
4. Suggest alternative
5. Rollback if necessary
```
