I had two remote interviews (Hiring Manager & Head of Engineering) and then a 7 h unpaid onsite. The scheduling was quick and the remote interviews were good (i.e. allowing both me and the company to investigate mutual fit). Unfortunately the on site part left a sour taste in my mouth. It started with a 3 hours of self-work on case study (in practice 2,5 of actual work, as the first half was an intro) followed by an hour-long break for lunch & lab tour. So far, so good - the case study was interesting and gave some insight into their day-to-day problem solving and the lab tour provided deeper context about the company. However after that it was 3 straight hours of interviewing without any breaks and with hardly any time for me to ask questions myself. I've left the office absolutely spent. I'm unsure if this level of induced weariness was intentional or not. A few days later I got a rejection, informing me that another candidate was selected. The "detailed feedback regardless of the decision" that was promised in the job posting amounted to three quite generic sentences. My request for anything deeper got ignored. Two months later the job posting is still open.