Confluent interview questions

The interview process took over a month. I received an email from a recruiter to schedule a call within a week of application. It was a generic screener call to check whether I satisfy the minimum requirements of this job. The next call was scheduled with the hiring manager (which I would say, was a mix of technical and behavioral questions) on a selected project from your portfolio. I received a design challenge the next day. The design challenge spanned for a week, and they were pretty open to answering any questions or doubts. Once I submitted the documents for the challenge, I was notified that they want to schedule a couple of more interviews. The interviews were supposed to be based on the design prompt or on the projects on my portfolio, but those focused on generic app critiques and product thinking exercises. I received a reject soon after these interviews. No questions were asked on the design prompt.