At Pier 70 in San Francisco, just a few steps from the Chase Center—home to Stephen Curry’s Golden State Warriors—there is a veritable startup factory running at full speed. This is where Y Combinator (YC), the world’s most famous startup accelerator, is now based. Since its creation in 2005, this Californian breeding ground for tech giants has helped launch companies such as Airbnb, Stripe, Coinbase, Twitch, Reddit, Instacart, Dropbox, and Deel. These success stories made us eager to discover YC from the inside—a chance made possible through a “Learning Expedition” organized this March by the French investment platform Fundora.
From the outside, however, nothing suggests a hub of cutting-edge innovation. While the building is विशाल and industrial, there is no sign indicating that dozens of ambitious young entrepreneurs are inside, working relentlessly to get their startups off the ground. Only the presence of numerous cameras hints at the sensitive nature of the site, located in Dogpatch, on San Francisco’s southeastern waterfront.
From Mountain View to Dogpatch
Dogpatch, named after the stray dogs that once roamed its streets, was historically known for its shipyards and warehouses. During World War II, Pier 70 was one of the largest shipbuilding sites in the United States, employing 18,000 workers who built 72 warships for the Pacific front.
Since the 1990s, the neighborhood has undergone significant gentrification, and a new type of workforce has taken over. Y Combinator moved there at the end of 2023 after its CEO, Garry Tan, decided that San Francisco—not the legendary Silicon Valley—was now the place to be for building a startup in the age of AI.
For 17 years, YC operated at full speed in Silicon Valley, following its first four years split between Silicon Valley and Cambridge, Massachusetts. As early as 2013, however, it had opened a branch in San Francisco to be closer to its main investors.
Before fully relocating to Dogpatch just over two years ago, YC’s original campus was located in Mountain View, about an hour’s drive from San Francisco. Today, 335 Pioneer Way is quiet. Only a YC logo, a few photos, and some orange chairs remain, reminders of the accelerator’s glorious past south of the Bay. The iconic outdoor sign, however, continues to attract entrepreneurs.
Even today, many travel the 60 kilometers from San Francisco to Mountain View just to take a photo in front of the famous Y Combinator sign and post it on LinkedIn. It has become a ritual—even a pilgrimage—to seek the blessing of the tech gods and ride the wave of success.
“5% of Y Combinator Companies Become Unicorns”
And yet, Y Combinator represents just three months in a startup’s life. Three months may be short—but it can change everything.
In San Francisco, everyone we met who has gone through YC is unequivocal: there is a before and an after. At the mere mention of the accelerator, their eyes light up—even if the dark circles under them reveal countless sleepless nights spent surviving YC’s intense pressure.
Jason Freedman knows YC well. The American entrepreneur went through the program twice—first in 2009 with FlightCaster, then in 2012 with 42Floors, both of which he later sold. Today, he wants to give back what YC gave him. That’s why he launched Orange Collective just over two years ago—a fund made up of YC alumni to support AI startups founded by YC-backed entrepreneurs.
The fund now includes more than 150 YC alumni as limited partners and boasts a portfolio of 115 startups, including Starcloud, Vybe, and Hamming AI. Some of them may well become unicorns.
Ryan Bednar, Freedman’s partner at Orange Collective and himself a YC alumnus (2011 with Tutorspree, 2017 with RankScience), highlights a striking statistic: “5% of Y Combinator companies become unicorns.” This is all the more impressive given that between 200 and 400 startups join each YC batch every three months—four cohorts per year, totaling nearly 1,000 startups annually.
7% Equity for $500,000 in Funding
To support them during the three-month program, each batch is divided into three groups, each assigned a dedicated Partner who provides tailored advice to founders. Among YC’s Partners are notable figures such as Tom Blomfield (co-founder of Monzo and GoCardless) and even a French representative, Nicolas Dessaigne, who went through YC in 2014 with Algolia.
Startups accepted into YC must give up 7% of their equity in exchange for $500,000 in pre-seed funding—a model sometimes criticized given the short duration of the program and the large cohort sizes.
Nevertheless, given YC’s remarkable track record, it’s no surprise that entrepreneurs from around the world apply. But getting in is no easy feat. With an acceptance rate of around 1%, YC is not only one of the most prestigious accelerators—it is also one of the most selective. Tens of thousands of applications are submitted each year, making it extremely difficult to stand out.
A 10-Minute Interview That Changes Everything
If a founding team catches YC’s attention, everything comes down to a 10-minute interview with one of its Partners—or even Garry Tan himself.
John Banner, founder of fintech startup Respaid, recalls his experience. His company aims to tackle unpaid invoices for SMEs using AI. During his interview, Garry Tan gave him a surprising piece of advice: “He told me I had to launch in the U.S. within two weeks. I was stunned—I didn’t expect that—but it was good advice.” Today, Respaid counts major U.S. clients such as Microsoft and DoorDash.
But the interview can be intense—even brutal. “One of my best friends cried during his interview. He was extremely smart, but it’s a very tough experience,” admits Jason Freedman.
On paper, the process is simple: ten questions in ten minutes. But half of them focus on a single trait—determination.
“That’s the first signal we look for,” says Freedman. “Questions about how founders met, for example, help us assess their determination. The rest doesn’t matter much. We don’t focus on vision—that’s a trap. Otherwise, Airbnb would never have become what it is today.”
“It’s okay to head in the wrong direction—as long as you don’t stay there too long,” he adds. In the U.S., abandoning a failing idea is often seen as learning, whereas in France and Europe, unsuccessful attempts are still less valued.
How YC Transformed Airbnb and Stripe
Airbnb’s story perfectly illustrates YC’s impact. Originally called AirBed & Breakfast, the company offered air mattresses and breakfast alongside accommodation. It was during YC that the founders pivoted toward the model we know today.
“Brian Chesky slept on the floor while analyzing user feedback. What matters isn’t just revenue—it’s learning from users,” recalls Jason Freedman. “He compiled a long list of insights, including the fact that checkout was too complicated. After seven weeks, he questioned the need for breakfast—but thought they couldn’t remove it because of the name. Eventually, they did. Midway through the batch, ‘Bed and Breakfast’ was dropped. That was the first step toward Airbnb.”
Stripe offers another example. Founders John and Patrick Collison joined YC in summer 2009. “Patrick would go directly to customers and spend hours solving their problems. Clearly, it paid off,” says Freedman.
“YC Only Asks for Two Things: Write Code and Talk to Users”
Since 2005, more than 5,000 startups have gone through YC, with over 100 reaching unicorn status and a combined valuation of $800 billion.
For all of them, the experience boils down to simple principles—executed at extreme speed. “During the 11 weeks leading up to Demo Day, founders should focus on just two things: writing code and talking to users,” summarizes Freedman.
For three months, entrepreneurs live and breathe their startups. There’s little room for personal life or downtime. Even casual drinks become working sessions where founders troubleshoot technical and business challenges—often under the watchful eye of visiting investors.
Unsurprisingly, YC teams say these three months are often the most productive period of a founder’s life.
“The Stanford and Harvard of Entrepreneurship”
These intense 11 weeks culminate in Demo Day—the defining moment of the program. Founders pitch their companies to a curated group of investors, hoping to secure funding and accelerate their growth.
In recent years, French startups such as Photoroom (Summer 2020), Finary (Winter 2021), and Argil (Summer 2024) have gone through YC. “YC is like three months in a washing machine—we were in constant hackathon mode,” said Laodis Menard, co-founder of Argil.
After completing the program, Argil—aiming to become a leader in AI video avatars—raised €4.9 million from EQT Ventures, YouTuber Kwebbelkop, and Charles Gorintin, co-founder and CTO of Alan.
Ultimately, Y Combinator has become a kind of entrepreneurial passport in San Francisco. Attending YC is like going to school for success in tech—hence the idea of a “YC mafia” dominating the city.
“Y Combinator is the best way to build companies,” says Jason Freedman.
“The vision of Y Combinator is to become the Stanford and Harvard of entrepreneurship,” concludes Alan Huet, co-founder and CMO of Fundora, which pools retail investor capital into a single vehicle to reach sufficient scale for private equity investments.
Since last November, Fundora has enabled its community to invest in a fund composed of YC-backed startups—opening up access to this factory of tech champions that continues to fuel the legend of San Francisco and Silicon Valley.
