He's not joking though. I've experienced 3 rounds of stupid tricky questions followed by a 4 hour "take home" project at a UK startup in Deep Learning before they were willing to even send flight tickets to London, and the feedback I've received was so comical that I almost wrote a blog post about it (I still might). Another robotic startup in SV grills with 6-hour stupid codility tests as a first phase (i.e. waste 6 hours just as a handshake). Not sure if they think time grows on trees or people have no other things to do just to pretend a day has 48 hours. I took those to see what the interviews are these days to stay fit, and I must say it's like a panopticon of Google-wannabes for uncompetitive salaries and useless equity with bad liquidation preference.