Smart Contract Infrastructure in Financial Systems: Determinism, Security Boundaries, and Execution Guarantees

Smart contracts do not replace financial infrastructure but extend it into a different trust domain, operating as one component within broader systems including off-chain ledgers, custody services, and compliance layers. Deterministic execution is the foundation of contract logic, ensuring all nodes reach identical results through pure-function-like state transitions. A clear boundary exists between on-chain deterministic settlement and off-chain operational intelligence such as risk evaluation, compliance verification, and fraud detection.