Proton.ai Senior Software Engineer interview questions

Very disappointing experience! I went through all the interview processes, one initial, two technical and the last one with the CEO and Head of engineering. The first three interviews went good, and then came the last one, which they tell you there isn't any right or wrong answers and it's basically a 'vibe check' call. The main question by the interviewers is: "tell us about what you did from high school until now". At first I was a bit confused, but since I was interested in computer science all my life and had some early experiences with the industry I told my story. Throughout the interview I didn't get almost any questions, just some basic, boring questions like: "what type of student were you". Anyway, we came to the end and they asked me if I have some questions. I asked some very thoughtful and interesting questions which they themselves were positively surprised and praised them as unique and interesting questions. I got a positive vibe from them before we ended the interview and said I will be contacted by the company for the final decision. Two days later they send me a generic "unfortunately" email, that said that the process has ended and nothing more. I applied as a referral in this company and they didn't even bother to explain to their employee, why I was declined. I wasted 1 month to go through the whole process, only for this company (which they act as they have culture) to decline through a generic email. I want to point out that I've been involved in more than 30 interview processes in my life and I know when an interview call goes good or bad. This has been one of the worst interview experiences of my life!