Name: Backend Design
Author: Ttuandatt

Backend Design

Design and implement production-grade backend systems with the right architecture pattern. Use this skill when: building a new backend service or API, scaffolding NestJS modules/controllers/services, choosing between architecture patterns (Clean Architecture, Modular Monolith, Hexagonal, Standard MVC), designing REST/GraphQL/WebSocket APIs, setting up error handling/validation/logging, or structuring database and caching layers. Also use when user says 'create module', 'add endpoint', 'design API', 'backend structure', or asks about backend best practices. Includes architecture selection questionnaire. Primarily targets NestJS + TypeScript + Prisma but principles apply broadly.

Ttuandatt0 スター2026/02/22

職業
カテゴリ: アーキテクチャパターン

Design production-grade backend systems by selecting the right architecture, then implementing with best practices.

Workflow

Assess context → Run architecture questionnaire (or skip to default)
Select pattern → Match project context to architecture
Scaffold structure → Generate folder structure + boilerplate
Implement features → Follow pattern rules + API/DB/cache best practices
Validate → Run build + tests to verify

Architecture Selection

Ask user (or infer from project context):

Question	Options
Team size	Solo / 2-5 / 6-15 / 15+
Lifespan	Prototype / 1-2yr / 3+yr
Domain complexity	Simple CRUD / Moderate / Complex rules
Scaling plan	Single service / May split / Microservices

Design production-grade backend systems by selecting the right architecture, then implementing with best practices.

Workflow

Assess context → Run architecture questionnaire (or skip to default)
Select pattern → Match project context to architecture
Scaffold structure → Generate folder structure + boilerplate
Implement features → Follow pattern rules + API/DB/cache best practices
Validate → Run build + tests to verify

Architecture Selection

Ask user (or infer from project context):

Question	Options
Team size	Solo / 2-5 / 6-15 / 15+
Lifespan	Prototype / 1-2yr / 3+yr
Domain complexity	Simple CRUD / Moderate / Complex rules
Scaling plan	Single service / May split / Microservices

Context	Pattern
Solo, prototype, CRUD, ASAP	NestJS Standard
Small team, moderate, may split later	Modular Monolith (default)
Senior, complex domain, long-term	Clean Architecture
Many integrations, testability critical	Hexagonal

Style	When to use
REST	Default for all CRUD + resource APIs
GraphQL	Complex queries with deep relations
WebSocket	Real-time: notifications, live scoring, chat

Backend Design

Workflow

Architecture Selection

Backend Design

Workflow

Architecture Selection

Decision Matrix

API Design Quick Reference

Core Implementation Rules

Error Handling (layered)

Validation (4 layers)

Database (Prisma)

Caching (Redis)

Auth & Security

Logging

Testing (Unit + Integration)

Sessions

Docker Patterns

Autonomous Loops

Kotlin Patterns

Eval Harness

Golang Patterns