Saga
A pattern for multi-system business transactions that need atomic success-or-rollback across systems without shared transactions — typically with compensating actions.
A saga is a pattern for multi-step business operations spanning multiple systems where each step is a local transaction in one system; if a later step fails, compensating transactions undo the earlier steps' effects. Used when a global ACID transaction across systems isn't possible — for example, placing an order updates Dynamics 365 CRM, debits F&O inventory, charges the payment processor, and dispatches the WMS. The saga pattern guarantees the operation either fully succeeds or fully rolls back across systems. Two implementation styles: orchestration (central orchestrator drives the sequence, typically Azure Durable Functions) and choreography (no orchestrator; systems react to events, with rollback events triggering compensation). Orchestration is cleaner for most Dynamics 365 cross-system scenarios.