Schema migrations during rapid growth are usually of the ADD COLUMN type which is cheap & easy. Data migrations are about the same amount of effort either way.

Schema migrations during rapid growth are usually of the ADD COLUMN type which is cheap & easy. Data migrations are about the same amount of effort either way. If anything, requiring explicit schema migrations forces you to think more carefully about your schema design decisions and saves headache down the road, as the article mentions Etsy (and many others) encountered.