1. Slack Ceo Stewart Butterfield
2. Stewart Butterfield Bio

After Flickr was acquired by Yahoo in 2005, Butterfield went back to the online game idea, only to fail again. But the office messaging platform Slack rose from the ashes of that second failure — a. SAN FRANCISCO — Stewart Butterfield, chief executive of the workplace collaboration app Slack, once offended Robert De Niro at an awards event with an irreverent comment, prompting the actor to.

WSJ. Magazine’s 2015 Technology Innovator and co-founder and CEO of Slack believes in the power of play

THE OFFICES OF SLACK, in the tech-centric SoMa district of San Francisco, feature endless swaths of bare wall-to-wall carpet awaiting the installation of desks and chairs. Wires hang loosely from ceilings, eager to attach themselves to future computer workstations. Blank whiteboards idle at the edges of soon-to-be-bustling rooms. These are anticipatory spaces—the headquarters of a company poised to explode with new hires.

Slack stands on the precipice of product mega-fame. There’s a decent chance you haven’t heard of it yet, and it sounds almost banal in description: software that helps groups of co-workers exchange instant messages and swap electronic files. Yet Slack is, by some estimates, the fastest-growing business application of all time. Slack’s customer base has expanded tenfold in the past year. Its 1.25 million users now include employee teams at Samsung, eBay, Pinterest, Deloitte, Harvard University, NASA’s Jet Propulsion Laboratory and the U.S. Department of State. More than half of its customers are outside the United States—Slack has offices in Dublin and Vancouver and is looking into the possibility of establishing outposts in Melbourne and Tokyo. In April, Slack received a new round of private investment that valued the company, which is not yet two years old, at $2.8 billion. It had been valued at $1.1 billion a mere six months earlier.

Why is Slack taking over the world? First, it minimizes the need for email. From casual check-ins to corporation-wide announcements, from newly posted automated reports to the latest pictures of your colleague’s cute new baby, Slack has now become the place where office workers can huddle, kibitz and learn from one another. And second, Slack users quickly come to see it as not just another software tool they’re forced to keep tabs on, but rather as the new office water cooler—a fun place to hang out and be part of their work community. “The whole spectrum of communication across a company can happen inside Slack,” says co-founder and CEO Stewart Butterfield, 42. “All those heterogeneous messaging schemes disappear.” Slack has indeed become such a deeply engrossing, near-addictive addition to the modern office that an internal memo Butterfield circulated to his staff was titled “Slack as a Distracting Menace.”

The phrase suggests the sort of wry, self-searching mind-set Butterfield is known for. On a weekday morning, behind a conference room door labeled solely with an emoji (the “tada” emoji, which features erupting confetti and streamers), Butterfield is drinking espresso shots and revving into an animated discussion that is not about venture capital, or customer adoption rates, or employee efficacy or even the hazards of always-on connectivity. He’s instead musing on the essential difference between living and nonliving things as understood by 19th-century scientific thinkers.

It turns out this topic was central to the thesis Butterfield wrote while earning a master’s degree in philosophy from Clare College, University of Cambridge. “You’ll never have a Newton for a blade of grass,” Butterfield says, paraphrasing Immanuel Kant by way of elucidating the rich complexities of this subject and his interest in them. “You’ll never have that precise, crystalline explanatory power of what life is—even when you consider the most basic of life forms.”

Butterfield is compact and somewhat manic; he’s prone to leaping suddenly from his chair to draw an illustrative graph that requires him to uncap multiple colored markers. In conversation, he flaunts a wide-ranging, hyperactive intellect that spews references to quantum mechanics, genetic homologies, eudaemonia (a Greek word meaning “human flourishing”) and the analytic philosopher Hilary Putnam. Despite his eclectic, far-ranging knowledge base, he also manages to be casual and self-deprecating. “Ultimately,” he concludes with regard to his thesis material, “the difference between a living thing and a nonliving thing is that the living thing is alive. And so I wrote 30,000 words on that.” As to why he abandoned academia for a life in the tech industry, forgoing his Ph.D. so that he could move to Vancouver and begin designing software and Web pages? “There’s not a lot of opportunity in philosophy, outside the big five philosophy firms, of course.”

“ An internal memo Butterfield circulated to his staff was titled ‘Slack as Distracting Menace.’ ”

It can be difficult to reconcile the elements of Butterfield’s wonky, ivory tower past with his go-go, Silicon Valley present. Here’s a man who dedicated years of his life to head-in-clouds academic pursuits. Yet now he builds practical tools to enhance the brute productivity of the corporate world. Likewise, you might be surprised to learn that Butterfield was born to countercultural parents who named him Dharma Jeremy Butterfield—before he renamed himself Stewart at age 12 because it was the least weird name he could think of. He spent his earliest youth in a log cabin in western Canada with no running water, phone or electricity. The nearest other child lived miles away. Yet now he harnesses sleek, cutting-edge technology in the service of better connecting people who sit at adjacent desks.

Perhaps the oddest irony of Butterfield’s career is a repeated disjunction between intent and results. Twice now Butterfield has tried to build wacky computer games—frivolous, pointless entertainments set in imaginary realms. Yet both times he has ditched those games to instead build software of powerful, real-world utility.

It happened first in the early 2000s, when Butterfield and some pals began to make something called Game Neverending. (The team included his then-wife, designer-entrepreneur Caterina Fake, with whom he had a daughter in 2007; the couple separated soon after.) This was an online, massively multiplayer game that, by all reports, offered no real objectives or endpoint—not unlike Minecraft, a best-selling video game that debuted a few years later, in 2009. “We had some strong beliefs about what we wanted the game to be, which was noncombat, noncompetitive world-building,” says Cal Henderson, who worked on Game Neverending and has stuck by Stewart’s side, eventually becoming Slack’s co-founder and chief technology officer. “We thought that was a less niche idea than it turned out to be. In fact it was a disaster, and soon we had no money.”

Desperate to find side revenue so he could keep paying his employees, Stewart bulked up an ancillary project the team had been toying with. At the dawn of the digital camera, before Facebook existed, they’d invented a neat way to share photos online. This became Flickr—a hugely successful photo-hosting site that was bought by Yahoo in 2005 for an amount Butterfield has previously said was “somewhere between $22 million and $25 million.” Butterfield and his crew went to Yahoo under the terms of the sale but didn’t stick around. Butterfield’s whimsical 2008 resignation letter to Yahoo is now legendary. “As you know, tin is in my blood,” it begins. It goes on to posit a fictional universe in which Butterfield joined Yahoo in 1921, back when “it was a sheet-tin concern of great momentum, growth and innovation.”

Out on his own again, Butterfield re-gathered much of his gang and sought investment for a new endeavor. Bradley Horowitz, now vice president of streams, photos, and sharing at Google, had worked with Butterfield at Yahoo and didn’t hesitate to bet on him. “I’d been blown away by his unconventional way of approaching problems,” says Horowitz. “I didn’t know or care what he was going to build; I just wanted to be a part of anything Stewart was leading.” Funding in hand, Butterfield vowed to take another shot at making Game Neverending, certain he could make it work this time. The resultant game, retitled Glitch, let players cultivate plants, talk to rocks, sing to butterflies and meditate. There was no fighting—really, no conflict at all. It was not exactly Grand Theft Auto. And over time, it became clear that Glitch, like Game Neverending, would never be profitable. “We’re terrible at making games,” says Henderson. So they shut it down.

Glitch might have been too gentle for this world. “Stewart’s a hippie,” Henderson explains. (It’s no accident that Slack’s official corporate values include empathy, courtesy, solidarity and playfulness.) But for the second time, Butterfield managed to spot the viable business lurking within the failure. The Glitch team, spread out in different cities, had been communicating using a system they’d rigged for themselves—a platform that allowed them to quickly form chat groups and share files with one another. Now they funneled all their efforts into making it something businesses might buy. “People have a lot of trouble recognizing that their beautiful idea, the one they’ve been nurturing for years, didn’t work,” says Amy Jo Kim, a start-up coach who helps entrepreneurs develop products, and who has known Butterfield socially for years. “Stewart has the humility to say, ‘I wasn’t as brilliant as I thought I was,’ and then to let go and find the phoenix in the ashes.”

“I’m opportunistic in the face of catastrophe” is how Butterfield puts it. “We noticed a virtual circle,” he says, “where the more that people hung out in our messaging system, the more features we wanted to put into it. And the more features we put in, the more people wanted to use it. We all agreed that, whatever we did next, we’d never want to collaborate again without using a system like this. So we thought it might be valuable to other people as well.”

He underestimated just how valuable. Slack’s biggest selling point is that it’s an email killer. Email’s a horrible way to communicate within a big organization, as each new message that comes in receives equal weight in your in-box, whether it’s earth-shattering news or a notice that the coffee machine is on the fritz again. Firms that start using Slack report that they send nearly 50 percent less email, resolving issues inside different channels on Slack instead. Workers save time that was once spent deleting emails like, say, “Subj: Anyone heading out to lunch?” and can instead peek into the “Lunch” channel on Slack if they’re looking for a sandwich buddy.

People using Slack quickly come to appreciate its slick interface. They can integrate other kinds of business software in powerful combinations, without ever leaving Slack. They can effortlessly form new sub–chat rooms that bring smatterings of colleagues together to solve a pressing problem. It all flows seamlessly between desktop at work, laptop at home and phone in between. Organizations discover that their workers spend time within Slack not just out of a sense of duty, but because they want to be where all their work pals are hanging out. The average user logs 10 hours per weekday connected to the system. (Slack is free to use, but a paid version unlocks more features, including enhanced searchability.)

Butterfield used to play in improvisational music groups, and he frequently mentions live jams as akin to the workplace—both contexts where it’s important to pay attention to what others are doing, and to find complementary roles for everyone that help push the collective to greater heights. “A lot of the value in Slack is in transparency,” he says. “It’s easy to duck into channels and get a sense of what’s going on all over the company, without having to read every email.”

Over time, users even find themselves harboring affection for Slack. It’s a cheerful environment—full of cheeky emojis and GIFs and a goofy “Slackbot” that’s ready with an automated quip. Slack just seems to make people happy. Eighty percent of customers in a recent survey felt Slack had a positive influence on their workplace culture.

“An enterprise collaboration software product is not something you expect people to love,” says Horowitz. “But people actually evangelize Slack and talk about its transformative powers. Partly it’s the tone. Stewart is such a jokester, and that voice comes through in Slack—his wit and his playfulness.” From the color palette to the eccentric bot that walks you through your first log-in to the quirky messages that greet you when you log in each time after that, Slack has personality. “Not many people can build things at Internet scale,” says Andrew Braccia of Accel Partners, the biggest shareholder in Slack, “but still be able to recognize the tiny details that go into making a community grow.”

Slack Ceo Stewart Butterfield

This is the kind of enterprise software that gets made by a philosophy major. And, noticeably, by a lover of games. Asked to name Slack’s predecessor, Kim points not to messaging systems but to Minecraft—which has no built-in missions but which players can “mod” to suit their own predilections. Likewise, Slack users create custom emojis of their colleagues’ faces and program the Slackbot to chime in with snappy jokes when certain trigger words are mentioned.

“Play is a really fundamental activity that’s perhaps underappreciated in mainstream culture,” says Butterfield. “It’s a great basis for human interaction. Playfulness means not just silliness but an experimental attitude. Looking at the world sideways and being curious.” Slack can sometimes feel like a game—one where the other players are your colleagues, the mission is always changing, and the objective is to treat one another with kindness and produce wonderful things together.

Stewart Butterfield Bio

“It’s like he’s secretly still making Game Neverending,” says Horowitz. “He’s the ultimate jester: Instead of us going to the game, he just made the game us.”