The year was 2008, and at Justin Kan’s Y Combinator–funded livestreaming site, Justin.tv, the end of the week meant only one thing: Fine Alcohol Friday. The ritual began when someone—Kan doesn’t remember who—sent a bottle of Johnnie Walker Blue Label to the company offices. “It wasn’t even that good, to be honest,” he recalled.

Justin.tv was only a year old at the time, and still six years away from morphing into the livestream juggernaut Twitch, now owned by Amazon. But that whiskey bottle kicked off a Friday afternoon tradition that fell right in line with Justin.tv’s work hard, play hard ethos. Surrounded by his fellow brogrammers, 23-year-old Kan was “living my worst life,” his exploits often fueled by copious amounts of booze. “We could go out together, get drunk, hit on girls, work on startups—awesome,” Kan’s co-founder, Michael Seibel, recalled in 2012.

“There was a drinking culture in the beginning,” Kan admitted over a recent phone call. “I didn’t know any better.” On average, Kan said he used to indulge in three drinks per night, five nights a week. But in 2019, five years after leaving Twitch, he went dry entirely. “I realized there wasn’t anything left in drinking for me,” he said. He’s been sober ever since.

In this and other ways, Kan was a pioneer in today’s Silicon Valley. Once marked by booze-soaked ragers to celebrate a funding round raised, a sales benchmark reached or a unicorn status achieved, the Valley of today has become a much less besotted place. “Remember a few years ago, there was a flush of cash in the tech scene, and you would see these companies having alcohol-fueled ragers and people would be having sex in the stairwell?” said Darren Marble, CEO of fintech company Issuance. “That’s not a good thing, right? That’s not a healthy part of the startup culture.”