Domain Modeling Layer 2: Design Choices Core Question What is this concept's role in the domain? Before modeling in code, understand: - Is it an Entity (identity matters) or Value Object (interchangeable)? - What invariants must be maintained? - Where are the aggregate boundaries? --- Domain Concept → Rust Pattern | Domain Concept | Rust Pattern | Ownership Implication | |----------------|--------------|----------------------| | Entity | struct + Id | Owned, unique identity | | Value Object | struct + Clone/Copy | Shareable, immutable | | Aggregate Root | struct owns children | Clear ownershi…