Recruiter reached out via LI a year ago, wasn't interested at the time. Year later when I was looking for a new role, reached back out and scheduled first round. Recruiter was absolutely amazing throughout the process, very communicative and prompt and always gave me good advice. Second and third round was with a manager who was newly moved over from Salesforce. Unfortunately like much of what you're reading here on Glassdoor, Slack is trying to incorporate Salesforce as much as possible through sales ops/upselling/pretty much everything, and that has changed the Slack culture as well. The manager I interviewed with clearly knew what she was doing, was well versed and a Salesforce OG, but at the same time I thought she was very hardcore and big tech-y. Which isn't a bad thing at all, but bringing that type of vibe and management style to smaller company like Slack will have its pros and cons. She grinded me a whole lot, and was one of the most difficult interviews I had, even going over 15 minutes each round. Final presentation was with the manager and a VP, where you had to prepare a powerpoint presentation of why they should choose you, and come up with template/prepare for a sample discovery call. I thought my discovery call/presentation went pretty well, but I messed up some objection handling. I did not end up getting the offer, but overall really enjoyed Slack's recruiting process, and it's no hard feelings as it wasn't meant to be. The recruiter and managers were all very kind, knew Slack top to bottom, had some worries about the Salesforce integration, but overall could not have asked for a better experience despite not getting the final offer.