Griffin – A fully-regulated, API-driven bank, with Clojure

Nor will there ever be, just by the nature of those systems.

You can't get deterministic execution from a system that uses non-deterministic request ordering, task scheduling, etc. -- which is what you get if you always use multiple OS threads, or spawn multiple discrete processes in tests, and so on.

I mean, I guess you _can_ make that stuff deterministic, but it would require you to build synchronization points into every transition in your application state machines, in a way that would be controllable by tests, which is a very tall order!

In practice, the only way to do this kind of thing is to design the core of your system to be fully synchronous, and to make it concurrent by adding concurrency at higher layers, expressed at run-time.

Column – a chartered bank for developers

https://news.ycombinator.com/item?id=31109170

Suppose you go to an online exchange or Bitcoin ATM or local man with a crypto wallet, you hand over five $10 bills or transfer some money from your bank account, you get $50 in cryptocurrency.

Now you go to the adult bookstore's website and don't have to give them your name, you send $20 to your friend in a foreign country so she can get a cab to the airport without having to lose another $15+ to a wire transfer fee, or you just use it to pay for parking.

Even if you screw up entirely, the most you're out is $50. But then nobody is tying your literature preferences to your name, you can do your friend a favor more efficiently, and the credit card company doesn't have a database of where and when you park your car.

The trust issues come when you want to be a speculator holding a large amount of wealth in a form someone could steal by breaking into your computer, but what does that have to do with using ordinary amounts day to day as a currency?

I'd love an example of this! I concede that I could be wrong on the point's of ML/Haskell families, however, it relies on the practitioner correctly using the type system to the extreme (at least, that is my impression). C++ and other similar OO's, the type system isn't as compelling as a correctness measure.

> On the contrary, they're still the most effective technique we've found for improving program correctness

In which domain are you working in where this has been the case? It may be my experience, but types as I have seen them used in industry have been more as "data containers with some behaviors".

I'd appreciate some examples of where you think I may be getting types wrong or missing the point.