V1 Senior Full Stack Developer interview questions

5 stage interview with HR, CTO, Developers, Product team and CEO. Also involved doing a skills test which took upto 2 days. The experience interviewing with everyone was pleasant except for the final round with the CEO. Overall seemed very disinterested and smug on most occasions. Remarked at one point that i was making bad faces which i did not know what to make of. At the end of this lengthy process all i got at the end was a boilerplate email saying they were going to look at other candidates. I tried following up with HR to get more info on why i got rejected after making it all the way to the final round with them but got no response. At the end the experience was disrespectful and very unprofessional.