Silicon Valley's Secret Work Schedule: The 72-Hour Week Taking Over AI Startups

Silicon Valley once promised that AI would make us work smarter, not harder. Now, tech startups are reviving a brutal 72-hour workweek that was banned in China for resembling modern slavery—and in San Francisco, they're succeeding.

The Rise of 996 in Tech

The so-called 996 schedule means working from 9 a.m. to 9 p.m., six days a week. It gained traction after Martin Mignot, a partner at venture capital firm Index Ventures, wrote in a LinkedIn post that it has "quietly become the norm across tech."

New research supports this claim. Spending data from payments firm Ramp shows a noticeable uptick in company card transactions on Saturdays this year, compared to previous years. Most of the increase was in restaurants, delivery services, and office catering—spending that typically indicates employees are on the clock.

Ara Kharazian, an economist at Ramp, called this change "extremely surprising," noting that such deviations are rare in large economies like San Francisco. He emphasized that this trend is unique to San Francisco, not occurring in New York, LA, Austin, or Miami, giving the 996 culture a "measurable signature" in Silicon Valley.

From China to San Francisco

The 996 schedule originated in mainland China, where tech companies once viewed excessive work hours as a key to success, endorsed by moguls like Alibaba founder Jack Ma. However, it led to protests, accusations of modern slavery, and even worker deaths. In 2022, China's top court ruled the schedule illegal and a violation of overtime laws.

In San Francisco, the story is different. Job ads warning of long work hours are increasingly common. For example, software biology firm LatchBio specifies in its listings that employees work Monday to Saturday in the office. Corgi, an insurance startup backed by Y Combinator, gives new hires a mattress as a welcome gift.

Inaki Berenguer, a tech founder and partner at AI venture fund LifeX Ventures, shared a personal anecdote: at a recent Sunday birthday lunch, friends left immediately after eating to return to the office. He noted that in 2016, long hours were for founders and senior employees, but now, in many AI startups, Sunday is for in-person meetings and reviews for everyone.

The Human Cost: Burnout and Inequality

Dominic McGregor, co-founder of Social Chain, highlighted the growing pressure for employees to work founders' hours, stating, "The weekend is disappearing in tech." He stressed the importance of fair compensation, warning that without share options and strong salaries, this intensity leads to attrition and burnout.

Even founders are not immune. A 2023 survey of over 400 founders found that 72% reported overwork harming their mental health, and more than a third suffered from burnout.

The weekend schedule also disproportionately affects women, who are more likely to be caregivers. This is reflected in Pitchbook data showing that women-only-founded U.S. startups raised just 2% of venture capital funding in 2024. Amelia Miller, co-founder of Ivee, criticized 996 culture for implying that success is only for "a young, white male with an Ivy League education."

Why Now? AI Hype and Job Market Pressures

AI was supposed to reduce work, not increase it. So why are hours piling up in Silicon Valley? One reason may be that the technology isn't delivering on its promises. Building real-world products still requires extensive engineering and trial and error. McKinsey reported that 80% of firms using generative AI see no material impact on earnings, and DeepMind CEO Demis Hassabis warned of industry hype.

Berenguer attributes the trend to a hyper-competitive environment where dozens of AI startups race to ship similar products. Some founders believe that speed—and the grueling hours it requires—is their only edge, as "these are winner-take-most markets where speed matters above everything."

However, the AI boom started in 2023, yet the Saturday spending data only emerged this year. Kharazian links the rise of 996 culture to return-to-office mandates, with AI startups accounting for about 15% of office leases in San Francisco in early 2025.

Another factor is the job market. The unemployment rate for recent graduates is 4.8%, above the overall average, and postings for junior roles fell 7% over the past year. With fewer opportunities, employees may be more willing to accept punishing schedules to get ahead.

Kharazian summarized, "If you've felt the city's weekend hustle returning, it's now quantifiably true. As for whether it's good for you, it's a conversation between you, your doctor, and maybe your founder."