An agent can now change your whole persistence stack in one pass.
Ask Claude Code or Codex to "add a plan_tier to accounts and wire it through," and it will read the repo, edit the Drizzle schema, generate a SQL migration, update the dbt source, touch a model, regenerate the TypeScript types, add a test, run the build, read the failure, and fix it. Multi-file, coherent, green. A year ago that was an afternoon; now, in a well-shaped repo, it's a prompt.
For a while I read that as pure upside — schema changes stopped being bottlenecked on how fast a human can hand-write a migration. Now I think the upside came with a quieter inversion: the same speed that makes good changes cheap makes unsafe changes cheap too. And the unsafe ones are exactly the kind that pass review, because they look consistent.
I've written before about handing agents short, verified facts instead of asking them to be careful. This is the same argument aimed at the database — the place where a confident wrong move is most expensive. It's a working theory, not a universal rule.
Where I've landed for now (and expect to keep revising):
