With tap-to-pay, you can store multiple cards in your digital wallet, and you don't have to remember any of their PINs. You can use your fingerprint to sign transactions. I believe this makes it faster.
Asynchronous and parallel programming are concepts I've never really learned, and admittedly scared to use, because I never really understand what the code is doing or even the right way of writing such code. Does anyone have any good resources that helped you learn this and have a good mental model of the concepts involved?