Why I Built a Visual Layer for Rails Migrations (And Why Reading Ruby DSL in a Diff Wasn't Enough)

Three months ago I merged a migration that added a null: false column with no default value. The table had 800k rows. Production broke, and the worst part wasn't the bug itself — it was that nothing in our workflow could have caught it. I was staring at a GitHub diff, reading raw Ruby DSL, trying to mentally reconstruct what the table looked like before this migration and whether the change would blow up on existing data. That's the review process most Rails teams rely on: hope that someone caf...