[justfor1comment]

This may be obvious to the candidates but it isn't that obvious to startups. I have seen startups that ask the same interview questions asked at FB. Why would anyone who can solve these questions join your loss making startup? IMO startups should scale the difficulty of their interview process with the liquid compensation they are willing to offer. Also, reduce the number of steps in the interview, especially for experienced candidates. Make the process smooth and effortless for the candidate. That's something FB and Goog cannot do at their scale.