Last week I turned my data audit into a build step: a check that runs before anything else and fails the build when the database and any static copy of my travel site's legal-status data disagree. It ended the era of the site contradicting itself.
It did nothing about the site agreeing with itself on something false.
That's not a hypothetical. The most expensive error the whole project found was a country whose law changed in January while every copy on my site — database, data files, search index — kept saying the old thing in perfect unison. Internal consistency was the camouflage. No diff between my own sources could ever have caught it, because every internal source was equally behind the world.
A build gate proves agreement. Agreement is not truth. Something has to look outside.
You can't diff against the world, but you can sample it
