Originally Posted by
cjw2001
The actual mechanics of it all are in Google Play Services (paired closely with the operating system) so the Google Wallet and Google Pay apps were always just user interfaces on top of that. That's why you could have both installed at the same time before the Google Pay app was killed off.
You can actually store cards and pay without either app installed by using the notification shortcuts that take you to the underlying bits.
Wow, interesting! Very cool, thanks.