How Digital Money Really Works

If you have a burning question about how money works, Patrick McKenzie probably has the answer. The software engineer/blogger/vaccine database founder’s widely read newsletter, Bits About Money, is dedicated to thinking about the often-misunderstood concepts at the intersection of tech and finance—or, as he puts it, “the modern financial infrastructure that the world sits atop of.”

McKenzie started his career as a “salaryman” in Japan, working 19-hour days before quitting to work for himself; now he advises payment processor Stripe Inc. in addition to software and writing work. His real passion, though, seems to be making sense of what happens when you tap “pay” on your phone. Our conversation with him has been edited for clarity and length.