The First Move When You Inherit Someone Else's Data

You just accepted a data warehouse handover. Maybe it is a consulting firm transitioning out, a platform migration, or an acquisition integration. Within weeks, a user finds a bad report and your team takes the blame for problems that existed before you arrived. Every data quality problem in that environment becomes your liability to explain and fix. I have seen teams skip the right first step and spend years in that position.

Profile the data before you sign the transfer. Learn what the existing data hygiene issues are and set up automated tests so you know when something drifts once you take control. Now you have evidence, not opinions.

TestGen, DataKitchen’s open source data quality tool, automates profiling, captures a baseline, and alerts on drift after handover. Connect it to the environment before the handover completes. Capture the null rates that break downstream reports, schema violations that crash pipelines, anomalous distributions that skew analysis, and referential integrity failures that corrupt joins. Get a dated record of what you are inheriting, then set up tests so any drift shows up immediately after you take over.

That record is your protection. When a user discovers a bad report six months from now and fingers start pointing, you produce a report dated before day one. Garbage in, garbage out becomes a documented fact rather than a retort. I have seen others walk into escalation calls with that dated report and walk out absolved. One meeting ends with blame. The other ends with the record speaking for itself.

Profile first. Take the keys second. Then keep improving the data quality.