Event Driven Orchestration

Durable orchestration runs on the current-lean orchestration platform (Temporal — open, ENG-01 §4/Decision Register ENG02-25); asynchronous messaging runs on the current-lean messaging technology (Azure Service Bus / Event Grid — open, ENG-01 §4/Decision Register ENG02-25). PH-04 itself does not select an orchestration vendor (PH-04 §1). PH-04 is the durable Product workflow that drives a Payment Request from creation through funding, claim, payout, and correction, calling into PH-03/PH-05/PH-06/PH-07/PH-08 as activities along the way.

Domain Events

Governed by the transactional outbox standard (STD01-10) and event context (STD01-04). Every material-event publisher (PH-03, PH-06, PH-07, PH-08 into PH-09, and others) implements it. Not yet built.

Listeners

Governed by STD01-05/STD01-10 (idempotent, at-least-once consumption) and ENG01-05. Not yet built.

Evolution

Governed by STD01-09 (event/contract schema evolution). Not yet built. (The platform's longer-run monolith→microservices evolution is a different, larger-scale question than event-schema evolution.)