As described in that book, definitely Google. I wouldn’t be surprised if the canonical coding interview as we know it today started at Google, but there is also the infamous technique used by Joel Spolesky, FitBizz or something like that.
I interviewed for Google in 2007. Got asked a bunch of typical coding questions, which some people might label "leetcode style", but they were questions you'd see in 1st/2nd year CS homework assignments.
But then, one interviewer asked about a graph theory problem which the first step was to first find all the strongly connected components and group them to one, and then required a couple more non-obvious proofs of specific properties of the graph to get to the solution. Definitely significantly harder than the typical "leetcode hard" questions.
