Your switchback looks significant — do you believe it?
Decide from resultsHardProblem. A switchback shows a significant +2% on-time improvement. Before you recommend rollout, what would make you doubt the result, and how do you check?
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.