After recruiter call, which went very smoothly and professionally, there is a hiring manager interview. The recruiter walked me through what to expect and how to prepare for it. I was initially set to interview with a manager, and few hours before the interview I was told they are switching up the person who should be interviewing me, because the manager in not available. The replacement was a developer and not a manger, and although I was told by the recruiter that this interview will be only behavioral and not technical, the interviewer expected to hear about technical aspects on each and every question they asked, and when you are trying to communicate the behavioural aspects in your answers, you don't feel the necessity to dive deep in technical aspects of the problem. There were also technical irrelevant questions in the interview which was unexpected and surprising. The interviewer was indirectly doing a tech screen and not a behavioural interview, which would have been fine if I knew this is not a behavioural interview, but wasn't the case. They were unmotivated to hear any of the answers, would tell me to give a different and more technical example of the situation because the one I talked about wasn't exciting enough for them, and they looked very distracted 5 seconds into my answers, which made me feel very uncomfortable. Overall the process was handled very unprofessionally specially for a company like Slack.
I then heard from the recruiter that they are not moving forward with the process because "the team" has decided I am not a good fit with no feedback, while the team was just one developer whose total years of development experience was half what I had.