DraftKings Senior Software Engineer interview questions

I applied to DraftKings through a referral. I was scheduled a 30 min call with a recruiter which went well and then a technical interview with an engineer. I showed up to the interview and the other engineer was nowhere to be found, after about 15 minutes I was told that there was a mistake and the engineer is on vacation so we need to reschedule. Now at this point I feel like they probably rushed to find someone for the interview the next day, because once the interview started, after explaining the problem, he proceeded to mute himself, look at another screen and start eating. I tried to explain my thought process but it was clear the other engineer was not really listening or interested. I finally managed to get him to talk by asking a question about the direction I am going and he gave me a little hint. I finished the technical question 10 minutes early, and then he asked me if there is any way to improve my code. I immediately realized that I can remove a for loop to bring my runtime down to O(nlogn). I explained it to him and said I can make the change right now but he said no need. Then he asked me about the runtime and I started analyzing it to show my thought process and he did not let me finish. At the end he highlighted the code which I assume was to copy and show it to others even though he did not let me improve it. The whole interview seemed very unprofessional and strange. It is possible I just got unlucky with my interviewer. Also the question is through HackerRank which is not ideal. The unfortunate part is that I told the first recruiter that I had applied to other positions within the company so she made sure that I will be considered for all of them through this one interview, which is a shame based on how it went. My previous experience was very relevant to the job and I had heard good things about working there.