7 production-tested Cursor Rules — dependency discipline, error handling, state management, webhook security, and more. Free sample from the full 50-rule pack.
## Parallel Data Fetching Pattern
```typescript
// ✅ Parallel — ~90ms total
const [user, posts, analytics] = await Promise.all([
getUser(userId),
getPosts(userId),
getAnalytics(userId),
])
// ❌ Sequential — ~230ms total
const user = await getUser(userId)
const posts = await getPosts(userId)
const analytics = await getAnalytics(userId)
```
## Error Result Pattern
Return typed errors instead of throwing everywhere:
```typescript
type Result<T> = { ok: true; data: T } | { ok: false; error: string }
```