[nolim1t]

For payment processing, I've built in a system which uses stripe (credit cards only) and bitcoin (using a different API. But that is only to detect whether payment has received. If the API is down, the detection of payments can still be done manually thanks to the fact that the bitcoin network is decentralized).

I never rely on a single point of failure. And of course, always good to have a "plan B" in place.