Q is one most important language here at BitMEX. Complicated or not, it's on KDB that all our trades happen, up to $8B in 24H volume last summer - it's highly efficient at its task, and never made us or any of our customers, loose a single Satoshi.
With all due respect, requests to BitMEX during times of high load have >50% probability of hitting a 503 Service Unavailable error. Meanwhile, competitors with similar volume/activity don't have this problem.
They've done studies, you know. They say 60% of the time, it works every time.