Temporal

Temporal workflows (Java SDK)

House patterns

• SAGA: register each compensation before its forward step, reconcile unknown financial outcomes before reversing, and run compensations in reverse order. Catch the SDK failures produced by the actual call path; never swallow replay or cancellation failures.
• Retry profiles - choose by side-effect class, not by service:
  • LIMITED - external-API writes: a small bounded attempt count, provider-aware backoff, and durable idempotency.
  • DEFAULT - internal idempotent operations, still bounded by workflow deadlines.
  • READ - transient reads only when retries cannot amplify load or violate provider limits.
• State machines: when several real brands or jurisdictions share a proven configurable shape, pass a validated immutable versioned config snapshot into the workflow; otherwise use plain code.
• Spring wiring: use the repository's version-compatible Temporal Spring integration and worker registration. Workflow code never touches Spring beans directly; activities may.
• Versioning: use Workflow.getVersion for command-producing behavior changes that old histories can replay through. continueAsNew carries forward only durable state.
• Signal races: wait for domain queues to drain and, when handlers can block, Workflow.await(Workflow::isEveryHandlerFinished) before completing or continuing as new.

Before writing code

Read references/temporal-patterns.md - versioning rules, continueAsNew criteria, child-workflow vs activity decision rule, fail-closed dynamic dispatch, and the failure-modes table (symptom → diagnosis → fix).

Tests

Use TestWorkflowEnvironment for changed workflow behavior, ordering assertions for sagas, and recorded-history replay for command-affecting version changes. Add only the proof relevant to the change.