Stewart Butterfield is a Co-Founder and serves as Chief Executive Officer and Chairman at Slack. He also serves as an Advisor at SignalFire. Prior to this, he served as the Senior Director of Product Management at Yahoo, as well was President and Co-Founder of Ludicorp Research and Development. In addition to these positions, he also worked as the Managing Director and Company Secretary with Gradfinder.com. He holds a BA degree in Philosophy & English from University of Victoria and MPhil in Philosophy from the University of Cambridge. [Source: Public Company Filing]