I had a 30 minute screen and then over the course of a day 3 competency based interviews, a systems design interview. This included lunch with an employee in the middle

I applied online and got a call back right away. The first was a 30min behavioral interview with the director. She was very nice and we had a nice chat. At the end told me someone from another team would reach out to setup another interview. I took it as another informal chat, to get to know the different teams. The second one was also another 30min behavioral interview with a manager/director. Very nice guy and we chatted about my leadership style as well as some themed questions drawn from my past experiences The third was an all day interview. I saw on the schedule that it was with 4 different groups. I had studied really well for it, so I was ready. The group of interviewers consists for 3 behavioral and situational questions. Sprinkled in some technical architecture. Each of of them had 2 interviewers per session. Then one last one at the end was the Systems Design Interview. It was with two software engineers. They mentioned that one of them (mostly quiet) was assessing the other (mostly the facilitator) since he was new. I thought the design questions went very well. I was able to answer most of their questions, while sometimes pulsed checked if I was on the right track. Everything seemed great. We chatted a little bit about how well they get along with their managers and if they enjoyed being part of the company (putting on my manager hat). After everything, it was about 3-4 week process, I felt very good. I was starting to get very excited to have a chance to work there. But after about 3-4 days of being ghosted by the recruiter, my mind started to change. Maybe they went with someone else better? Maybe I had said something wrong with one of the interviewers? One of them didn't like my personality/experience? Then about 1.5 weeks after my last interview, the recruiter wrote an email saying they will not be moving me forward in the process. She also asked if I would like to setup a time for some feedback. I was disappointed, but didn't want to drag out her time, since they obviously didn't want to hire me. I wanted to know how I could have improved, so I asked her to provide some specific feedback by email. She never did and I never heard from her again.