There are two rounds. First round is a one-on-one Skype with a manager. The length is 45 minutes and you can expect about 10 minutes of resume/fit and 35 minutes of case. The case scenario is a mix of qualitative/business acumen questions and quantitative scenarios. The priority is setting up the problem correctly not necessarily doing the calculation right. The second round is a day of interviews at the Wayfair office. There are three 45 minute interviews with members of the team. One is behavioral/fit and two are case interviews. Expect to combine analytical knowledge with basic calculations of some KPIs of your choosing (Click through rate, conversion rate, average order value, etc.).