The amazing life of Stewart Butterfield, the CEO of one of the fastest-growing business apps ever

By Maya Kosoff

Before building his $2.8 billion startup Slack, which many consider the fastest-growing business app ever, Stewart Butterfield ran another hot startup called Flickr, which was sold to Yahoo for over $20 million.

He also has a master's in philosophy, with a focus on biology, cognitive science, and philosophy of mind.

But his path to success wasn't so straightforward. Along the way, Butterfield grappled with trying to fundraise for a startup in a post-tech bubble landscape. He also had to pivot a struggling gaming startup.