A schema rename passed every unit test. It still broke a revenue dashboard.

The query changed from order_total to gross_amount; the schema was valid, but downstream models still expected the old field.

The fix isn't another linter. Before merge, ask four questions:

Which assets depend on this field?

Is the change additive, rename, type change, or removal?

Can we generate compatibility SQL and dbt YAML before touching production?

Is there a decision receipt reviewers can reproduce?

I built a bounded public replay of that workflow. Start with the CRITICAL case: it blocks a lossy decimal-to-integer change when an ML consumer sits downstream, then exposes the lineage, affected queries, compatibility artifacts, and deterministic run ID.

Demo: https://schema-shield.vercel.app Source/evidence: https://github.com/ceodaradigu/schema-shield

What schema operation should the next fixture cover?

AI-assisted analysis, reviewed before publication by RELAUNCH DEPT.