The tech industry couldn't stop talking about "founder mode" in 2024 — but Bill Gates embodied it decades ago.

Y Combinator cofounder Paul Graham coined the term to summarize advice from Airbnb cofounder Brian Chesky. Graham wrote in an essay that Chesky mentioned Steve Jobs at Apple as an example of a founder who took a hands-on approach to running their company.

Gates, who built Microsoft in the 1970s, was similarly intense when it came to making his budding company successful as a university student. In his new memoir, "Source Code: My Beginnings," the 69-year-old billionaire recalled the early days at the company, which he said required 80-hour workweeks and a limited social life.

"I had always been the taskmaster, the one who incessantly worried about losing our lead, and fearing that if we weren't careful, we'd be sunk," Gates said.

He said he was "driven by the sense of responsibility" he felt for Microsoft's success.

As Graham wrote in his blog post, manager mode describes a boss who delegates duties to his employees. Founder mode, however, is for leaders who are detail-oriented and don't use multiple layers of management to keep their companies afloat.

"If I could summarize founder mode in a couple sentences, it's about being in the details," Chesky said on The Verge's "Decoder" podcast.

"It's that great leadership is presence, not absence," he added.

Gates' social circle in 1976 was almost exclusively the men he was working on Microsoft with — "no girlfriend, no hobbies." By shutting out the rest of the world, he wrote, he could focus on making the most of the opportunity ahead of him.

Meanwhile, he questioned the dedication of his Microsoft cofounder, Paul Allen. He said that Allen didn't share his level of ambition to be the fastest and the best.

Gates said he needed a "twenty-four-hours-a-day business partner," and Allen wasn't prepared to be that partner. Eventually, he'd find that ideal partner in fellow Harvard student Steve Ballmer.

In January 1977, Gates dropped out of college to pursue Microsoft full time. His work would lead to it becoming one of the biggest companies in the world.

"Yes, it was exhausting, but it was also exhilarating," he wrote.