I built software for the self-service automats of a very large European rail company, and I remember spending whole afternoons testing every possible scenario l

I built software for the self-service automats of a very large European rail company, and I remember spending whole afternoons testing every possible scenario listed in our testing book. Those required manually purchasing tickets to many different cities, using the credit card terminal on the machine. They even had fake Discover, VISA, Mastercards you were to use to make those test purchases (to this day I don't know who came up with those fake cards and how that part of the system worked). But no, not everybody tests payment in production. It was a while ago, but I don't think they'd have switched the entire philosophy by that much since then.