n&k Technology interview questions

HR recruiter gave me a screening call where we talked about my resume. Most of the questions that he asked were very relevant to the job posting itself. He was very friendly and easy to talk to without a hint of hostility. Although he assured me that we will move onto the next stage of the interview process, it took over two weeks for the second call to confirm the in-person interview time.

As the previous reviews, this was the worst interview I ever met. There is no phone interview, the HR called me and invited me to a 1-to-1 interview directly. I was astonished by the unprofessional questions asked by Dr. Rahim Forouhi. At the very beginning, he asked "Why don't you marry an American to get green card?""Are you married?""Do you have child? How old is he?""Can you work with a 2-year old child?" I don't think these kind of questions regarding privacy should be asked in an interview. After 30 mins talk, Dr. Forouhi asked me to write a algorithm in my PhD work. Since I'm from a totally different field, I begin with the questions "Have you heard XXX equations?" He didn't answer me. So I said "That's fine, we can consider the equations in this simple form" and write down a equation. He suddenly got so angry and said "You shouldn't ask me any question! You should just answer my questions." I tried to explain that I just wanted to make sure that he understood the background so that we could jump to the core algorithm. If he never heard about these equations, I could have a brief introduction. But he didn't listen to me, just repeated "You should just answer my question. This is interview. No communication. You are here to find a job. You are not here to ask questions." I don't understand why he is so angry by a question. I said I'm sorry that I didn't answer your questions and tried to continue introducing my work. Then I found a typo and fixed it. He interrupted me again "See, you equations are wrong! And you ask me if I understand?" I made this typo because of his interruption. So I didn't want to explain any more. I believe interview is for both interviewer and interviewee to learn each other. And by communications, I can learn the personality of my future colleagues. But Dr. Rahim Forouhi said "We don't need communications. I'm not your colleague." I'm not sure if he is having some difficulties in his life. I can't believe a co-founder would have such value. I couldn't agree with the culture in this company and apologized to him that I have to stop the interview because I felt lack of appropriate respect. The HR is nice. I thanked for their time and left after 45mins awful experience.