Coordinating Across Services
Distributed transactions, choreographed saga (+ payment), orchestrated saga (+ shipping), failure modes and the resilience chassis.
Distributed Transactions, the Saga & Extraction 4 — Payment (choreographed)
ACID gives way to ACD; checkout's synchronous 201/402 contract becomes an asynchronous 202/PENDING handoff; a choreographed saga captures payment, confirms or compensates, and the equivalence suite is taught to verify an outcome it can no longer observe on the same request.
Orchestrated Sagas & Extraction 5 — Shipping (Camel Saga EIP)
Shipping becomes a bounded, orchestrated saga: a single Camel Saga EIP coordinator sequences dispatch and owns the compensation decision, in contrast to Chapter 23's choreography; the cross-context undo is delegated to the order context that owns the data it must reverse, and the equivalence suite is extended to prove it net-zero across an even longer chain.
Failure Modes & the Resilience Chassis
Partial-failure taxonomy; timeouts, retry + jitter, circuit breaker, bulkhead, load shedding; SmallRye Fault Tolerance as the Quarkus chassis.