FinTech Domain Layer 3: Domain Constraints Domain Constraints → Design Implications | Domain Rule | Design Constraint | Rust Implication | |-------------|-------------------|------------------| | Audit trail | Immutable records | Arc<T , no mutation | | Precision | No floating point | rust decimal | | Consistency | Transaction boundaries | Clear ownership | | Compliance | Complete logging | Structured tracing | | Reproducibility | Deterministic execution | No race conditions | --- Critical Constraints Financial Precision Audit Requirements Consistency --- Trace Down ↓ From constraints to desi…