The interviewer mainly asked me to talk about my research projects, and he asked questions from time to time. The style might be subjective to the interviewer. Some interviewer might ask several small questions, e.g., ask about ML basics.

Asked my project on my CV, like what is the motivation of the work, what are some technical details, e.g., and then extended to other ML background questions, what method can be used to replace RLHF.