Like it or not, this particular hiring filter seems to have caught on bigtime. The only downside to it is that there are people like myself who love to take a stab at solving puzzles regardless of whether they actually want the job or not. In the past 2 years, I solved online puzzles & scored interviews with the founders of 3 yc companies ( greplin, poundpay & freshplum) & 4 giant financial shops ( BlackRock & 2 other hedge funds I can't name/nda). In some cases like BlackRock, the puzzles are quite involved & can take a week to complete. Puzzles are a lot of fun....I just wish the associated job was equally interesting.