Job 4817 was submitted exactly once, and it produced three emails, two database rows, and one very confused customer. The log said timeout after 30000ms , the database said duplicate key , and for three hours those looked like two unrelated incidents. They were the same bug, and it appeared the...
Source: [Dev.to](https://dev.to/robinzzz/make-retry-idempotency-an-invariant-before-you-move-a-batch-job-to-a-free-model-endpoint-ad0)