Stewart Butterfield on Slack: Founder Calls His Own App Terrible

Stewart Butterfield is the proud founder of a billion-dollar “giant piece of shit.”

Vancouver’s Butterfield says Slack—an app that reached the billion-dollar valuation mark faster than any Canadian startup ever—is “terrible.” In an interview with the MIT Technology Review, Stewart hinted not-so-subtly at future changes after saying that he tells his team they should “be humiliated that we offer this to the public.”

There’s a huge amount of stuff we’re working on, from things like message replies and the ability to react to messages in a nonverbal way … We’re probably about halfway through the list of things we wanted to do when we started two years ago. We still have a long way to go.

Slack last month raised $120 million in new investment in a round that was co-led by Kleiner Perkins Caufield & Byers and Google Ventures with the participation of all existing institutional investors and a few new ones, including Yammer founder and former PayPal COO David Sacks.

Launched publicly in February 2014, Slack is used by 30,000 active teams to send 200 million messages each month. The growth to date has been entirely organic; the company has yet to hire any sales or marketing staff. Driven by recommendations from existing users and near-perfect retention rates, Slack’s growth has resulted in high conversion to paid tiers: more than 73,000 of its daily active users are paid.

“The world is in the very early stages of a 100 year shift in how people communicate, and we’re determined to push the boundaries,” Stewart Butterfield.