One traveler, three cookies: design a personalization test that doesn't leak
Experiment designHardProblem. The team wants to test a new personalized search ranking that uses travelers' profiles from the customer data platform. Many travelers browse on several devices and brands, some signed in, some not. If the test randomizes by cookie, what goes wrong, and how would you design it instead?
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.