---
title: Organize Code by Feature Using Vertical Slices
impact: CRITICAL
impactDescription: Dramatically improves discoverability and reduces cross-team conflicts
tags: architecture, vertical-slices, organization
---
## Паспорт документа

- Статус документа: living standard
- Актуально на: 28 марта 2026 года
- Владелец: backend/platform-команда
- Пересмотр: при изменении инженерной практики, CI/CD, архитектурных правил или локального workflow
- Область применения: внутренние rule/reference-card документы для инженерной команды
- Связанные документы:
  - [Индекс Agents](../README.md)
  - [Команды разработки](../commands.md)
  - [Инженерные принципы](../../governance/engineering-principles.md)

## Organize Code by Feature Using Vertical Slices

**Impact: CRITICAL**

Code is organized by feature/domain, not by technical layer. Each feature in the NestJS backend is a self-contained module. On the frontend, components are colocated with their pages.

**Incorrect (traditional layered architecture):**

```
src/
  controllers/
    catalogController.ts
    sellerController.ts
  services/
    catalogService.ts
    sellerService.ts
  repositories/
    catalogRepository.ts
    sellerRepository.ts
```

This creates problems: changes to one feature require touching files scattered across multiple directories.

**Correct (vertical slice architecture):**

```
# NestJS Backend
src/modules/
  catalog/
    catalog.controller.ts
    catalog.service.ts
    catalog.module.ts
    repositories/
      catalog.repository.ts
    dto/
      catalog-filter.dto.ts
      catalog-response.dto.ts
  seller/
    seller.controller.ts
    seller.service.ts
    seller.module.ts
    repositories/
      seller.repository.ts
    dto/
      create-seller.dto.ts

# Next.js Frontend
app/
  item/[slug]/
    page.tsx              # Server Component
    ClientItemView.tsx    # Client Component (interactivity)
  seller/
    items/
      page.tsx
      new/page.tsx
components/
  CourseCard.tsx           # Shared across features
  FilterSidebar.tsx
```

Each feature module is self-contained with:
- **Controller**: HTTP layer (thin, delegates to service)
- **Service**: Business logic and orchestration
- **Repository**: Data access (Prisma queries)
- **DTOs**: Input validation and response shaping
- **Tests**: Unit and integration tests for the module