I'll echo that, as someone who's hired a bunch of people at tech companies (much smaller than Google). It's always subjective: who has a good personality and who's maybe a little too weird or antisocial. Who excels at which parts of the interview - there are always a few, and you almost always get mixed results. This person seems especially bright, but that person has the experience we're looking for - how do we weight those against each other? How much money do we have in the budget? - oops, this person seems great, but they're way out of our range. How much do we decide to care about the fact that you were nervous, or you were five minutes late, or about how much you actually read up on the company beforehand? Do we care if you have a degree or not? Some places care a lot, some don't care at all. Even if you have a standardized way of grading candidates, there's no one objective score for "this is the best person for the job." There's always personal judgement involved, and if you don't stop to consider that, it's easy for your brain to default to, "well, people like me are the best people, because I think I'm pretty awesome and I like to hang out with people I have a lot in common with." That's only human, but it's something to be aware of.