I was asked by HR if I wanted to do a task before talking to her. As I was looking to understand the opportunity better I asked to talk to her first and during that chat she told that I was internally being considered for a position that was different than the one I applied to and that I would have been invited for an interview with a lead. However, I later received a task that asked me to dedicate about 3-4 hours of my time to understanding the brief and coming up with something that explained how I would approach the problem. After delivering what requested and having asked in vain for confirmation of the interview I was promised, I received a vague email telling me that they were no longer considering me. When I asked for a more in-depth feedback I was pretty much told that some other candidates provided more detail and that is what they were looking for (not the process/approach apparently). I find that design challenges that take the form of an homework are much less effective than whiteboard. In this case, it was also a waste of time because the way they treat this step of the process was not transparently communicated....but maybe they don't really have a process as it seems they quickly change their minds and don't keep their words.