Googler here. I want to apologize for the way that the recruiters and interviewers treated you. There were several anomalies in the story you describe. The delays in were unacceptable. There should only be one phone screen in most cases. At some point, without telling you, my guess would be that they transfered you from one job ladder to another (the second round of phone screens) even though you seem to have qualified for on-sites with the first two phone screens. The second two interview questions that you got were also unacceptable because they tested for prior knowledge, not general capability. Also, I have never seen an interviewer care about testing (but I never interview for the Software Engineering in Tools and Infrastructure ladder—maybe it happens there).