Switchback or cluster? Design the unbiased feed test
Experiment designHardProblem. You have established that buyer-randomized feed tests are biased upward. Your PM asks for a design that measures the real launch effect. What do you build, and what does it cost?
Before you reveal: say your answer out loud, as if you were in the real interview — get your reasoning across clearly first. There is no single correct answer: reading what the interviewer is really after and defending your own thinking is what makes an answer strong.