(If you do happen to know the origin story, I’d love to read it).
Hiring a programmer? Ditch the coding interview and get back to basics
Dan Kim

Supposedly, this started off in the 70s/80s when IBM needed programmers, but no one knew programming straight off of college. So, they used to hire on the basis of aptitude ‘Tests’ (kinda like he infamous “why are manholes round” questions). Eventually, the people working at IBM went on to become middle managers at Microsoft, Sun etc and made hiring decisions. The people hired by these managers are now themselves managers at Facebook. Google etc and thus this elaborate hazing ritual continues.