I don't know how much computing power is actually needed when you're just buying BTC. When I used Coinbase recently to take a small BTC position, I only made maybe 4 transactions in total. Is this really a lot to handle?
I'd imagine you can't use scaling tricks like eventual consistency or simple sharding here. Traders are going to be pissed if their most up to date information from the exchange is a second behind what they can see.
It's already at the point where they have a line in their FAQ for the GDAX API that tells people where to colocate from for the lowest latency.
And all of that data needs to be stored damn-near indefinitely, and securely. And integrated with traditional financial systems.
I'd love to see some information on what it actually takes, as i'm just guessing here, but seeing as there aren't any bitcoin exchanges that can seem to keep the servers running smoothly during spikes, i'm guessing it's not a trivial problem to solve.
I'm not saying it's impossible, but the amount of growth they have seen is substantial and unprecedented. Nobody could have predicted it, and the rate of increase just keeps going up.
They are clearly new in this space, as all cryptocurrency companies are. I don't think that means that they should just give up and go home because they couldn't keep the servers up during spikes of insane activity...
And a lot more operating capital, too.
It's absolutely bonkers amounts of growth!
Edit: more concrete numbers:
In January of 2016 they had around 2.6 million users.
On November 29th they announced they had over 13 million users.