Integrations fail most often at the edges: timeouts, duplicate events, schema changes, and expired credentials. Reliability comes from defensive design, not optimistic assumptions.
Before launch, verify idempotency for all write operations, implement bounded retries with backoff, and isolate failed messages in a dead-letter queue.
Add observability from day one: request logs, success ratios, latency tracking, and high-signal alerts that point to specific failure modes.
A reliable integration is not one that never fails. It is one that fails safely, recovers quickly, and gives your team the context to act immediately.