You only have 2^10000 if you have bad boundaries and overcoupling of your subsystems. Thus another benefit of unit testing is validating your architecture: bad architectures are inherently difficult to unit test.
>bad boundaries and overcoupling of your subsystems
And that's the overwhelming majority of ways to make money with software. Think of every video game, desktop application, and mobile app that people purchase. What you call "bad boundary" isn't bad at all. The customers just expect the software to do 2^10000 combinations of possible things across N platforms on M hardware and integration with P external services. Imagine if you emailed a company's tech support saying that the CAD software you bought doesn't work with your Nvidia 1060, and they responded "sorry, that makes our sybsystems overcoupled".
This is true, but the interaction between the doctor and the nurse was invaluable. The context of those orders and the nurse's knowledge of the patient were used to come up with a plan together. Reducing that interaction to "order giver" and "order taker" greatly reduces the quality of patient care. I was recently in the hospital for a week and this was an issue several times.
That asynchronous behaviour happened in the paper world too. Make chart entries, send paper orders to pharmacy/lab, flag it for the other care providers.
Look lower down that thread for the FAQ from the company: they're using the roommate's Facebook account to purchase targeted ads on Facebook in order to evade Facebook's internal controls. https://www.reddit.com/r/Scams/comments/2vd1g8/scam_rentyour...
Since this is an API, that means you just build this into your app. You could initially decline the transaction, send a push alert to the user's app notifying them that the transaction is in review, then update them on that status when approved/declined. At that point the card can be run again and approved if that was the decision. You could even allow a pre-request through the app, when when approved would enable your user's card for the purchase. The possibilities are endless.
