I went through two rounds of interviews. TL;DR - they asked me to do a 6 hour "writing test" and then rejected me without any feedback. In the first round, 2 of my scheduled interviewers didn't show up or notify their coworker that they would not show up. That said, the woman who interviewed me was not prepared. It was completely disorganized. I made it to the second round - a 6 hour writing test. To comply with the NDA I signed, all I will say is that employers really shouldn't use interview tests to get away with hours of unpaid training. And, if you do ask an interviewee for an essentially full workday of labor, you do owe them prompt feedback on how they did. Some might assume you scammed them. I myself am undecided on that.