What problem does it solve? Data pipelines that append under retries, lose late-arriving data, or run destructive backfills silently corrupt production tables. This Skill reviews or designs batch and streaming pipelines so they are idempotent, restartable, and correct under retries and backfills. ## Core Features & Use Cases - Idempotency audit: Classifies every load as partition overwrite, MERGE/upsert, or unsafe bare append, and flags duplicate-row risks under retry. - Incremental correctness: Verifies watermark cursors use event timestamps, persist only after success, and include a late-data lookback window. - Orchestration and backfill safety: Checks Airflow, Dagster, Prefect, or dbt definitions for bounded retries, concurrency limits, deliberate catchup settings, and non-destructive parameterized backfills. - Use Case: A PR adds an Airflow DAG that loads orders hourly. Use this Skill to confirm the load uses MERGE on a stable key, the watermark persists after success, catchup is disabled, and a backfill plan targets only affected partitions. ## Quick Start Review the Airflow DAG and dbt models in this repository for idempotency, watermark handling, and backfill safety, then produce a findings report.