Web Domain Layer 3: Domain Constraints Domain Constraints → Design Implications | Domain Rule | Design Constraint | Rust Implication | |-------------|-------------------|------------------| | Stateless HTTP | No request-local globals | State in extractors | | Concurrency | Handle many connections | Async, Send + Sync | | Latency SLA | Fast response | Efficient ownership | | Security | Input validation | Type-safe extractors | | Observability | Request tracing | tracing + tower layers | --- Critical Constraints Async by Default State Management Request Lifecycle --- Trace Down ↓ From constrain…