## MOC: Backend-паттерны и архитектурные решения

### Слоистая архитектура

```mermaid
graph TB
    HTTP[HTTP Request] --> Chi[Chi Router]
    Chi --> MW[Middleware: Auth, CORS, Rate Limit, Logger]
    MW --> H[Handler]
    H --> S[Service: бизнес-логика]
    S --> R[Repository: PostgreSQL/pgx]
    S --> C[Cache: Redis]
    S --> FS[File Storage: MinIO/S3]
    R --> PG[(PostgreSQL + PostGIS)]
```

### Ключевые решения

| Паттерн | Где реализовано | Заметка |
|---------|----------------|---------|
| Sentinel errors | `services/*.go` | [[atomic-sentinel-errors-go]] |
| Dependency Injection (интерфейсы) | `services/*.go` | [[atomic-dependency-inversion-go]] |
| Graceful shutdown | `cmd/api/main.go` | [[atomic-graceful-shutdown]] |
| Refresh token rotation | `services/auth.go` | [[decision-jwt-refresh-storage]] |
| Rate limiting (Redis) | `middleware/ratelimit_redis.go` | [[decision-rate-limiter-redis]] |
| WebSocket origin check | `handlers/websocket.go` | [[atomic-websocket-origin-check]] |

### Error handling chain

```mermaid
sequenceDiagram
    Handler->>Service: call
    Service->>Repo: query
    Repo-->>Service: pgx error
    Service-->>Handler: sentinel error (%w)
    Handler->>Handler: errors.Is() -> HTTP status
```

### Тестирование

| Уровень | Инструмент | Пример |
|---------|-----------|--------|
| Unit (сервисы) | `testing` + моки | [[atomic-test-patterns-go]] |
| Integration | `testcontainers-go` | [[decision-test-strategy]] |
| E2E | Playwright | [[decision-test-strategy]] |

### Связанные заметки
- [[architecture-overview]] — общая архитектура
- [[backend-auth-security]] — JWT и refresh token
- [[backend-validation]] — валидация через go-playground/validator
- [[backend-rate-limiting]] — rate limiting
- [[deploy-production-readiness]] — production readiness

#architecture #backend #golang #MOC #best-practice