[christophilus]

I think Stripe was originally built on Rails (can’t find anything to confirm that at the moment). But my guess is they enforce things at the app layer, since Rails didn’t really provide a good way to enforce things at the DB layer originally. They support very old API versions by transforming requests backwards and forward through a list of API version transforms, which also suggests to me that this sort of thing is enforced at the app layer rather than the DB.