Apple Platform Software Engineer interview questions

Got contacted by HR via email, then I had a couple of phone screening with two different engineers, one hour long, both technical. Interviers were both very prepared, the questions were interesting, and gradually built up from basic knowledge to more advanced knowledge around the same topic. You had to type code using some live coding environment which allowed you to check the algorithm "in real time" (unlike Google), so that you ended up with a working solution at the end of the interview. The interviewers were both interested in assessing the technical capacity and the reasoning behind decisions (unlike Google interviewers that only wait for you to finish typing, copy paste your exercise and run it on their own machine). Never felt the sensation that I was being judged just based on that particular algorithm implemented, or only based on its formal correctness. HR is, on the other side, lacking proper feedback and quite unprofessional. They originally approached me, but after two weeks from their first email and my first reply, I had to chase them to confirm an interview date. When they came back, the first two interviews were scheduled promptly, but after that they disappeared again without even replying to a couple of emails I sent to ask for feedback. I didn't think I did a bad interview but I will never know why I didn't proceed to the next stages (they might have frozen hiring due to Covid for that position, for what I know).