Quant Developer

Surprisingly, Roberts said he used C++ sparingly. "I never really used anything very esoteric and, in fact, tended to rely on tools that were fairly common and unsophisticated. For example, back between 2001 and 2003, I wrote two entire HFT trading systems (one for option market making and the other for equity pairs trading) using VB6, which even back then would've struck many as silly. The reality was that the applications worked, they were reliable and they were fast (since VB6 is compiled)."

"Moreover," he continued, "I was very productive using VB6, which enabled me to get a lot more done than if I had attempted to build everything using C++. In fact, I would only use C++ for the very rare algorithm that needed an extra boost of speed, and the one I remember best as being slow in VB6 was the square root function, of all things!"

A Slashdot.org reader named "TheRaven64" said in the comments about my highest-paid-programmers article that "I periodically get contacted by recruiters for banks, because my CV mentions Haskell, and there's a massive shortage of Haskell programmers." 

The use of Haskell indicates that the new darling of the software development world, functional programming, plays a large part in the HFT industry. TheRaven64 said in his comments that recruiters who contacted him for possible employment in the financial industry "wanted people with any functional programming experience. A lot of these companies use their own in-house languages, but functional programming is popular because it's easy to verify functional programs, and because languages like Haskell facilitate rapid development. Cincom does good business selling Smalltalk to trading houses for a similar reason. Typically, a small improvement in a trading algorithm gives you an advantage for a day -- maybe less. Being able to go from idea to deployment in under an hour is something that Smalltalk and Haskell give you, and that's something that the financial industry values highly."

When one reader asked about the role of testing in such quick deployments, he was answered by yet another reader who said, "I think that was the point. Writing in one of these languages means that you can prove the correctness of the code, presumably automatically, so presumably very quickly."