The interviewer seemed encouraging, and wanted to know me as a person. First gave my introduction, then we jumped straight into DSA. He gave me 1 question, standard 0/1 knapsack problem. First told the brute force would be exponential then wrote the tabulation of the code. Then we went to OS and OOPS, basic stuff like public keywords, mutex and deadlock. Then asked if I had any questions, and ended the interview. Around 20 minutes max.
Intro followed by oops questions and difference between mutex and semaphores and os fundamentals like cpu scheduling algorithms etc and asked to code with any language of choice and discuss complexities