architecture

# System Architecture Skill

**Bonded to:** `architecture-patterns-agent`

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## Quick Start

```bash
# Invoke architecture skill
"Help me decompose this monolith into microservices"
"Which design pattern should I use for notifications?"
"Design an event-driven architecture for order processing"
```

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## Instructions

1. **Analyze Requirements**: Understand system needs and constraints
2. **Apply SOLID**: Use SOLID principles for clean design
3. **Select Patterns**: Choose appropriate design patterns
4. **Design Architecture**: Select monolithic or distributed approach
5. **Validate Design**: Review for scalability and maintainability

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## Architecture Selection Matrix

| Style | Best For | Team Size | Complexity | Scale |
|-------|----------|-----------|------------|-------|
| Monolith | MVPs, small teams | 1-10 | Low | Vertical |
| Modular Monolith | Growing apps | 5-20 | Medium | Vertical |
| Microservices | Large teams | 20+ | High | Horizontal |
| Serverless | Variable load | 1-15 | Medium | Auto |
| Event-Driven | Real-time, async | 10+ | High | Horizontal |

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## Decision Tree

```
Team size & complexity?
    │
    ├─→ Small team (1-5) → Monolith
    │
    ├─→ Growing team (5-20)
    │     ├─→ Clear domain boundaries → Modular Monolith
    │     └─→ Variable load → Serverless
    │
    └─→ Large team (20+)
          ├─→ Real-time/async heavy → Event-Driven
          └─→ Independent scaling needed → Microservices
```

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## SOLID Principles

| Principle | Description | Violation Sign |
|-----------|-------------|----------------|
| **S**ingle Responsibility | One reason to change | Class does too many things |
| **O**pen/Closed | Open for extension, closed for mod | Editing existing code for new features |
| **L**iskov Substitution | Subtypes substitutable | Subclass changes behavior unexpectedly |
| **I**nterface Segregation | Small, specific interfaces | Clients implement unused methods |
| **D**ependency Inversion | Depend on abstractions | H