Overall I had a great experience interviewing with Wayfair. For me, the process consisted of an initial case interview (plus standard behavioral questions involving my interest in the position and Wayfair), and a second round with four interviews. Two of these were additional case interviews, and two were behavioral interviews with cross-functional team members. The behavioral interviews were fairly standard (why Wayfair, "tell me about a time when...", etc.), and revolved around their People Principles. The case interviews all revolved around a problem Wayfair has seen before. They all felt very collaborative (I would propose some ideas for how to causally identify something, and the interviewer would go from there or provide additional clarifying questions). Questions got relatively detailed (what my data would look like, what standard errors I might use, what level of randomization I would choose if running an experiment / RCT, what assumptions would make my estimates causal, how I might select features in a model, etc.) but I felt comfortable to say when I would have to think about something more, and the interviewers were helpful in providing guidance and hints. Ultimately every interview felt very conversational and collaborative. Throughout the process the recruiter was very friendly and provided ample guidance to approach each interview. Post-offer everyone was incredibly generous with their time and with answering my questions.