The final interview was 5 hours long, with a 20 minute culture fit thing at the start, with the rest of the time alternating 45 minutes of algorithm questions and 15 minutes of general chat. It was, long, exhausting (stopped being able to solve algorithms about 4 hours in, brain started freezing), no-one showed any real interest in anything I'd done (there was one 5 minute chat about 4 hours in about a side project I did a year or before) and no-one explained what 5 hours of algorithm questions was meant to achieve. If they'd explained the format before I wouldn't have gone. It was really surprising, because the people seemed friendly. Seems like there's gotta be something pretty broken somewhere in the process to get good people to treat you like that. They also never got in touch with me to tell me if I'd passed or not. I never chased them up; if that's how they treated me before I started, imagine what'd it be like working there!