You don't understand. Not everything is written in C. There's a backend system for reporting OATS that starts at 5 PM. If you need to make a non-trivial change you better not deploy it during market hours. Most of these systems are written in Java by guys who aren't at the firm anymore and didn't care when they were. You say cutting edge (which I would strenuously debate). But it's not magic -- in fact it's actually quite mundane when you get down to the nuts and bolts.