The Prompt Changed, the Schema Didn't, and the Job Still Passed
python
dev.to
Version skew is the quietest bug class in model pipelines. Validation passes because the schema never moved. Your prompt did. That gap is where I lost a week. Here is the walkthrough, plus the harness I now use to catch it. The symptom: green checks, wrong totals The extraction job ran nightly. It pulled invoice lines and wrote normalized amounts. One morning the totals were low. No exceptions. No retries. No dead letters. The validator was happy. Every record had amount as a stri