Meta Machine Learning Software Engineer interview questions

I was interviewed previously for the same role in Sept 2020 but didn't get an offer. I was advised to wait a year before trying again. I did so and first needed to clear two preliminary coding interviews of about 45 minutes each. I was told that sometimes only one such interview is needed, but sometimes two are needed--as in my case--to generate sufficient "signal". After this stage, I was invited for an "onsite" interview. This was still physically remote from the office, but it was an all day interview similar to an interview that might be physically onsite. Due to time constraints, I wasn't able to prepare adequately for the onsite at the proposed time, and asked to postpone. I ended up postponing for many months, but did eventually reschedule the onsite. Despite the delay (initiated by me, not Meta) I was not required to repeat any of the preliminary steps, but went directly to the onsite. I was told that this was possible because it was still a bit less than a year since we initiated the process. The interview consisted of six individual rounds. Two were further coding rounds. Two were behavioral interviews (how I'd handled past challenges more of a human rather than technical nature). One focused specifically on machine learning and the other on systems architecture. At the end of the day my sourcer said that I would hear more within about 48 hours. I did indeed hear more quickly, but unfortunately the news was negative. The biggest concern was that significantly less feedback was provided this time as compared to when I interviewed previously two years ago. It is not so much that I expect specific feedback when turned down for a job--I know every company is different. But so much more constructive feedback was provided in Sept 2020 as compared to the next time in Sept 2022. This seemed a step in the wrong direction, and leaves me less enthusiastic about trying again a third time. Again--this is a different reaction than I had in Sept 2020 when the constructive feedback that time left me enthusiastic about trying again as soon as I got the chance. Overall--not a bad experience, but the lack of constructive feedback this time turned what was overall a "positive" experience into one I'd deem merely "neutral".