Is 800 transactions per second good? It seems like a low number but what do I know. I am impressed that Europe's largest betting system only does 800 transactions per second.
That's 800 credit card transactions a second --- thats people making deposits into their accounts to bet with. (btw I think that's peak - I'm not 100% sure)
The frontends (where the casino / betting games run) do a lot more than this, but they work against the balance in the account, it's the payment gateway that's doing 800/s
It was a bit simplistic of me to summarize it as a payment gateway, it was actually 50-60% of their backend systems that was enhanced, it was called their "Big Data Project"
They do do fraud detection on the deposits, because of anti-money-laundering. The DL models also monitor various other types of abuse (bonus abuse and in-game abusers). They also are experimenting with Deep Reenforcement Learning to actually play some of the games
Well, I think random forests on a feature set probably plays a big role and is probably easier. But to use a deep neural network maybe, you might be able to get away with a convolutional network to extract higher order associations among some input set.
An online betting system has to do fraud detection on a higher level than random merchants, since they can expect to be a target for large scale non-amateur fraudsters, and just as in any other business, if your incoming payments are fraudulent, you lose that money.