SiRIUS Embedded Software Software Engineer interview questions

Initially I got call from the HR. And got case study (first round) from the HR. Some how I solved it and got call for face to face interview. I had written test and then face to face interview after first round. The guy who took my interview doesn't know about linked list. He asked a question about linked list. I wrote the answer on paper. And again there was an argument related to the solution. Some how I explained him detailed with an example.