For hiring in the U.S., discrimination is legal if it's done on the basis of what are called "bona fide occupational qualifications". This is the legal princip

For hiring in the U.S., discrimination is legal if it's done on the basis of what are called "bona fide occupational qualifications". This is the legal principle that allows, say, police departments to reject people who don't meet physical standards, or modeling agencies to reject people just because they're ugly. You could make a good case that success on puzzle questions has a decent correlation with success as a programmer--that is, the ability to solve puzzles is probably a BFOQ for programmers, so it's safe from a legal standpoint.