My problem with that answer is that it doesn't tell me much about the engineer. It's a one sentence response and other than showing me that you know the right l

My problem with that answer is that it doesn't tell me much about the engineer. It's a one sentence response and other than showing me that you know the right library to use, doesn't show any other depth. It's one step above "I would google it". As you said, libraries require a good deal of machinery to integrate into your project, so just saying you'd use a library doesn't touch on any of the potential problems that project might have. If you happened to know that libraries API and could explain in some more depth how you would use that library, I would accept it, but I highly doubt most people would have API knowledge off the top of their heads, and I would be suitably impressed if they did. Ignoring all the other potential problems with Google's interview process, and the question of whether he should have been asked this for the position he was interviewing for in the first place (I can't say without knowing more details), saying I would use library X is a terrible answer to a question. The point of the interview is to get to know more about your skills and abilities, and a one sentence answer tells me almost nothing. Of course it is also partially the interviewer's responsibility to ask the right questions, look for the right qualities, and lead the interview in a way where the interviewee can properly demonstrate their skills, but it's also partially or equally the interviewee's responsibility to demonstrate that.