Stewart Butterfield

Stewart Butterfield was born Dharma Jeremy Butterfield on March 21, 1973, in Lund, British Columbia, and legally changed his first name to Stewart at age 12. He earned a B.A. in Philosophy from the University of Victoria (1996) and a Master of Philosophy from Clare College, University of Cambridge (1998), where his work focused on 19th-century scientific thinkers — a humanities background he frequently credits for his approach to product design.

He is a rare two-time category-defining founder. After co-founding Gradfinder.com (2000) and then Ludicorp (2002, with Caterina Fake and Jason Classon) in Vancouver, his team's online game "Game Neverending" pivoted into the photo-sharing site Flickr, which launched in 2005 and was acquired by Yahoo!; Butterfield served as General Manager until leaving in July 2008. In 2009 he founded Tiny Speck to build the online game Glitch, which shut down in December 2012 — but its internal communication tool became Slack.

Slack launched publicly in February 2014 and grew into one of the fastest-adopted enterprise software products ever. It went public via direct listing in June 2019, and in December 2020 Salesforce agreed to acquire it for roughly $27.7 billion. Butterfield stayed on as Slack CEO after the acquisition, then announced his departure in December 2022 and left Salesforce in January 2023.

Since leaving Slack, Butterfield has shifted into full-time angel investing, "quietly writing checks" into early-stage founders and joining syndicate deals, concentrating in the collaboration, developer-tools, productivity, AI, and fintech categories where his operating experience runs deepest. He is a Canadian billionaire and is married to Jennifer Rubio, co-founder of the luggage brand Away.

• Invests mainly at pre-seed/seed and early Series A, as a personal angel and via small syndicates rather than through a formal fund.
• Concentrates in areas of direct operating expertise: collaboration and workplace software, developer infrastructure, productivity tools, AI, and fintech.
• Favors B2B products in "unsexy" internal-tooling categories and companies that assume distributed/remote teams as the default — problems he personally lived through building Flickr and Slack.
• Reportedly weighs product obsession and user experience over raw growth metrics, strong distribution/go-to-market instincts, and founders who pivot based on data (the Flickr and Slack story is itself two successful pivots).
• Frequently co-invests alongside top-tier firms such as Accel, Sequoia, and Y Combinator-affiliated investors, indicating strong deal flow.