As others have noted, it is a multi step process. The first step is a somewhat easy case study that takes about an hour. If you pass that round, which most do, you get the week long case study. I wrote a 15 page report for this with extensive analysis. Unfortunately, I did not pass this round and got one sentence of feedback. Company seems like a great place to work, but I would reevaluate the interview process. Candidates put in many hours on the assignment and most do not make it pass this round. If they put in so much time for just an interview, I believe YipitData should speak to more of them. Or, make the first screen harder, so that only a few people get to do the week long assignment. Either way, provide much more feedback to the candidates who put so much work into the assignment. One sentence feedback is insufficient.

The interview process was very structured and conducted in a professional manner. First there was a talk with HR, and after that I had to a take-home assignment to assess some analytical skills. After it was approved, I went through a technical interview with a case study, and after that I went through two more interviews to assess soft skills and talk about my prior experiences in more detail.