Data catalog and lineage
A catalog tells people what data exists. Lineage tells them where it came from and what breaks if it changes.
Ask three teams for revenue and you’ll get three tables, built by three people who each didn’t know the others existed. A catalog is the fix: an index of what exists, what it means, who owns it, and where it’s safe to use. Dull, and worth more than most dashboards.
Lineage is the other half. Every field traced back through each transformation to its source, and forward to every dashboard and model that depends on it. When a source changes, you see the blast radius before the change ships. When a number looks wrong, you walk the chain instead of interviewing the company.
Both get wired into the pipelines themselves, so metadata updates as the data moves. Documentation maintained by hand is fiction within a quarter.