Slack interview questions

Pretty straightforward process. Applied online then received an email-response project. Got an email following to set up a phone call with the recruiter and we chatted for about 30 minutes about things like why Slack, my experience, examples of customer interactions. After that I was contacted to schedule a call with the hiring manager and it was generally the same. This felt less formal than the recruiter call - was mainly asked questions about myself, what I look for in a team, etc. The hiring manager had nothing but positive things to say about my answers and how that aligns with his team. I received a generic email a couple days later that they didn't find a strong match with what they're looking for at the moment. Great and positive experience up to that point. This is understandable if an application is rejected from the start but I went through a project and two interviews. Maybe I expected more based on all the wonderful things I've heard about Slack but this was an extremely negative experience for me and a miss on their part.