>But he also got about 30 people to spend four weeks building trading software for him.
I don't think he did. He got 13 people to work on problems for 3 weeks. (I assume the rest of the 30 bailed at some point).
They also weren't obligated to stick around (though it turned out valuable to them as well). And they picked up a new skill (APL programming). They also asked for it: "Twenty-seven of the applicants suggested I teach them all first and then make a hiring decision."
I don't think he did. He got 13 people to work on problems for 3 weeks. (I assume the rest of the 30 bailed at some point).
They also weren't obligated to stick around (though it turned out valuable to them as well). And they picked up a new skill (APL programming). They also asked for it: "Twenty-seven of the applicants suggested I teach them all first and then make a hiring decision."