Incredibly unprofessional behavior. I was invited to 2 interviews and after the last, I was asked to work on a case study. Upon sending it in, I received an answer that they will check it out and I will receive a call to discuss the results after holidays. Instead, I received no answer for two months, after which I received an email completely unrelated to the case study, asking about the courses I took at my University (5 years ago). After sending in the email containing these courses, I never received a single reply again. Very rude behavior, clearly this is not how you treat a fellow human being, and especially not in a supposed professional setting.