> Maybe you can tell us something about their coding practices. A friend of mine who work at GS told me they have an absolutely massive ball of spaghetti that takes 7 hours to compile. That's for their trading systems.

In case no one with actual experience responds to you, you might want to check out Flash Boys[0], which spends a little time talking about GS's code. From what I've read in that book and in other places, what you heard seems to be the correct.

[0] https://www.amazon.com/Flash-Boys-Wall-Street-Revolt/dp/0393...