The interview process at Slack included a phone screen, phone interview, onsite interview and timed Excel modelling exam. The People Operations team handling my interview process were very professional and responsive. They were engaged at each step of the process and quick to answer my questions. The interview panel was sharp and they didn't hold back pointed questions. They asked me to model financial statements on the white board during the onsite interview. They also were interested in my personal interests outside of work. Overall, I was impressed with the interview process at Slack and thought they did a significantly better job than some of the other firms I was actively interviewing with. The interview process left a positive impression on me and ultimately factored into my choice to accept their firm's offer.