SchemaSentry

SchemaSentry is a web app (with optional CLI) that continuously monitors your data warehouse/lakehouse tables and critical upstream sources for schema and contract drift. It fingerprints schemas, detects breaking changes (type widening/narrowing, nullability shifts, column drops/renames), and maps blast radius by tracing which dbt models, dashboards, and downstream jobs depend on the changed fields. When drift is detected, it opens actionable tickets (Jira/GitHub), posts Slack alerts with a suggested fix, and can auto-generate a PR to update dbt tests/contracts. This is a combination traditional + AI app: traditional for reliable detection and lineage, AI for summarizing impact, proposing migration steps, and drafting PRs. The MVP focuses on Snowflake/BigQuery + dbt first, because “support everything” is where these tools die.