Stewart Butterfield

Stewart Butterfield is a Canadian billionaire businessman, best known for co-founding the photo-sharing website Flickr and the team-messaging application Slack.

In the summer of 2002, he co-founded Ludicorp with Caterina Fake and Jason Classon in Vancouver. Ludicorp initially developed a massively multiplayer online role-playing game called Game Neverending. After the game failed to launch, the company started a photo-sharing website called Flickr. In March 2005, Ludicorp was acquired by Yahoo!, where Butterfield continued as the General Manager of Flickr until he left Yahoo! on July 12, 2008.

In August 2013, Butterfield announced the release of Slack, an instant-message-based team communication tool, built by Tiny Speck while working on Glitch. After its public release in February 2014, the tool grew at a weekly rate of 5 to 10 percent, with more than 120,000 daily users registered in the first week of August. In early 2014, the data for Slack's first six-month usage period showed that nearly 16,000 users were registered without any advertising.

That same year, Butterfield secured an office for Slack employees in San Francisco, and was expected to commence recruitment during the second half of the year.

As of December 2015, Slack had raised US$340 million in venture capital and had more than 2 million daily active users, of which 570,000 were paid customers.

Slack was named Inc. Magazine’s 2015 company of the year.

In June 2019, the company announced its initial public offering with an opening price of $38.50 and a market capitalization of US$21.4 billion.

In December 2020, Salesforce confirmed plans to buy Slack Technologies for US$27.7 billion.

In December 2022, Butterfield announced his departure as CEO of Slack and left Salesforce early in January 2023.