Had a first 30min call to explain me the role and the hiring process which went fine. Quite a long waiting process to hear back for the next step. The have full "work in office" culture coming from the very top. I've asked for some clarification questions during the process, but no answer. 2nd step was a written essay, as somebody already mentioned this here, and you have 1 week to complete it on 4-5 pages for a given use case. As I knew that, I've put in a few hours of work to do it well, but did not want to overdo it as you have to go through another 3 rounds of interviews. At the end they have just come back to me saying I don't qualify for the next round and that they have 9 months "cool off policy". I've ask for some feedback on my paper to learn on what I failed on, in order to not to repeat it, but they did not bother to respond. All in all, I don't think that you should bother with them as you will need to invest literaly weeks of good customized preparation and they show no sign of respect. Also if you don't make it, you can not apply for a new position for the following 9 months (who wants it any more after 9 months?!??), unless it's really the only AI company you want to work for and I don't see why this should be the case.