Integration Engineering

Treat an external system as an unreliable boundary with somebody else's domain model.

Workflow

1. Inspect the external contract, ownership, authentication mechanism, quotas/rate limits, and actual business job.
2. Map external identifiers/statuses/objects into an internal boundary model. Avoid allowing vendor-specific DTOs or lifecycle semantics to become the application's domain by accident.
3. Define timeout, retry, idempotency, duplicate, and partial-failure behavior for each operation that can repeat.
4. Choose webhook, polling, callback, or async/event mechanisms from the provider's actual guarantees and product latency needs.
5. Define reconciliation: how the application detects and repairs missed callbacks, stale local state, or ambiguous outcomes.
6. Identify observability needed to answer integration-specific questions without logging secrets/sensitive payloads unnecessarily.
7. Report supporting security, async-work, database, privacy, or reliability concerns to the active core workflow when they materially apply.

Stop

Stop when mapping, ownership, failure/retry, reconciliation, and evidence are explicit enough to implement or review the integration safely.

Reference Guide