Honestly very fair and pleasant. I'm more frustrated that while I was able to complete the three parts to the question, I had struggled to come up with a robust solution to meet the expectations for the role (I did a brute force method). This is the only company I've interviewed at where they actually gave me interview feedback after the interview. I felt that their justification for not continuing me through the process was fair (still disappointing but I understood why). It was DSA but within the domain I work in (web) so it wasn't straight-up LC.