Amazing life of Slack CEO Stewart Butterfield

Slack, the fast-growing workplace-chat platform with a $7 billion private valuation, filed the paperwork on Friday to publicly list its shares in a direct listing.Stewart Butterfield founded Slack in 2013 after selling his first startup, Flickr, to Yahoo for more than $20 million. Visit Business Insider's homepage for more stories. Stewart Butterfield is on a roll.Before building his $7 billion startup Slack — which many consider the fastest-growing business app ever, and which officially filed the paperwork to go public Friday — Stewart Butterfield ran another hot startup called Flickr, which sold to Yahoo for over $20 million.This time, Butterfield's exit promises to be much splashier. The workplace messaging app, born out of a now-defunct gaming startup Tiny Speck, will find itself in the spotlight when it has what's widely expected to be an exciting debut on the public markets.As 2019 shapes up to be a banner year for tech IPOs, Butterfield's journey to success stands out. Along the way, Butterfield grappled with trying to fundraise for a startup in a post-tech bubble landscape. And even should he successfully navigate Slack to a successful public debut, he still has to deal with the looming threat of Microsoft. Read More: Slack, the $7 billion office-messaging app that millennials and startups love, just filed to go public in a really weird wayThis is an update to a post by Maya Kosoff first published in 2015.