The tap takes a quarter of a second. The terminal beeps, the screen turns green, and the transaction is over as far as anyone standing at the counter is concerned. What actually happened in that quarter second involves at least five separate organizations, two distinct financial processes separated by a day or more, a set of message formats older than most of the people using them, and a chain of contractual obligations that determines who eats the loss if anything goes wrong. Almost none of this is visible, and most…
Payment Rails Explained: What Happens After You Tap
