domain-driven-design

# Domain-Driven Design Tactical Patterns Model complex business domains with entities, value objects, and bounded contexts. ## Overview - Modeling complex business logic - Separating domain from infrastructure - Establishing clear boundaries between subdomains - Building rich domain models with behavior - Implementing ubiquitous language in code ## Building Blocks Overview ``` ┌─────────────────────────────────────────────────────────────┐ │ DDD Building Blocks │ ├─────────────────────────────────────────────────────────────┤ │ ENTITIES VALUE OBJECTS AGGREGATES │ │ Order (has ID) Money (no ID) [Order]→Items │ │ │ │ DOMAIN SERVICES REPOSITORIES DOMAIN EVENTS │ │ PricingService IOrderRepository OrderSubmitted │ │ │ │ FACTORIES SPECIFICATIONS MODULES │ │ OrderFactory OverdueOrderSpec orders/, payments/ │ └─────────────────────────────────────────────────────────────┘ ``` ## Quick Reference ### Entity (Has Identity) ```python from dataclasses import dataclass, field from uuid import UUID from uuid_utils import uuid7 @dataclass class Order: """Entity: Has identity, mutable state, lifecycle.""" id: UUID = field(default_factory=uuid7) customer_id: UUID = field(default=None) status: str = "...