I don't think the point is that every interviewer should ask about Twitters source code, and every interviewee should memorize it. The point is to ask a few ra

I don't think the point is that every interviewer should ask about Twitters source code, and every interviewee should memorize it. The point is to ask a few randomly sampled knowledge questions to measure how well rounded the candidate is. Taking the "first 10 lines of Twitter" is just one way to sample such questions.