Google's hiring process seems very intense and extensive. Are there other tech companies that go to these lengths to find the right people? I completely understand their reasoning, but I have never applied at a company that had four interviews.
I had 6 on site interviews when I joined Yahoo Europe back in 2003 for an engineering manager position. Developers back then would usually go through fewer, but still 3-4 wouldn't have been unusual depending on team - when I hired for my team at Yahoo, typical process would've been phone screen, then 3-4 on site interviews with a selection of people including my manager, someone from the product team, one of my developers, and me.
It's a function of size, frankly - companies above a certain size tends to tack on more interviews largely because they can, and it doesn't hurt to get feedback from one more person. They also have the luxury (and problem) of a much larger pool of interested candidates to hire from.
