July 31, 2023

Want to get in Y Combinator? Don't do this

Five mistakes to avoid in your Y Combinator application, from someone who will be looking at it

Almost a decade ago, Nicolas Dessaigne was one of the few Europeans accepted to Silicon Valley accelerator Y Combinator. He joined the winter 2014 cohort with Algolia, the startup he cofounded to give developers tools to build search functions into apps and websites — now valued at $2.25bn. 

Y Combinator’s reputation as one of the world’s most prolific producers of successful startups remains unchallenged to this day.

In recent years, plenty more European founders like Dessaigne have also been through the programme. 


But getting in isn't any easier. Every batch sees about 10k applications and has just a 1.5-2% acceptance rate.

Now, Dessaigne sits on the other side of the table. For the past three years, he's been a group partner at YC, where he uses his entrepreneurial expertise to help the next generation of founders. He has already seen through six YC “batches” (or cohorts) — that’s hundreds of companies. 

“Group partners are error experts,” Dessaigne tells Sifted. “We’ve seen — and made — every possible and imaginable error.”

Thinking of applying to join YC's next batch? Here are Dessaigne’s top five mistakes not to make.

Don’t pass on technical talent

You’ll significantly increase your chances if at least someone on your team brings technical expertise, according to Dessaigne. It's frequent for a startup to pivot in its early days and you’ll need the flexibility to do this without outsourcing or recruiting for technical skills. In other words, fast-tracking growth requires the ability to autonomously adapt or build new products.

Bear in mind that this doesn’t necessarily mean you need a software developer. If you’re developing hardware or a healthcare product, for example, you’ll need a different set of skills.

Don’t come on your own

If you’re a solo entrepreneur, you better start looking for a cofounder. Dessaigne says that, from experience, achieving successful results is much harder when you’re on your own than when you’re in a team. “If you’re facing a solo founder, you’ll always ask: ‘Can this person succeed alone?’ — when you won’t be thinking this about a team,” he says. 

👉 Read: There are only two accelerators European VCs care about

These are only flags — not red flags, caveats Dessaigne. YC has backed solo, non-technical founders like Ryan Neu, the founder of SaaS procurement company Vendr, who came from a sales background and went through YC in 2019. That success story, however, is the exception and not the norm, Dessaigne says.

Don’t get ChatGPT to write your application

It might seem obvious, but joining YC requires a professional level of English — and you won’t be able to fake it. Smiling, Dessaigne says he's had surprises before. Applications come written in “beautiful” English, but founders struggle to keep up in the follow-up interview. You can certainly ask ChatGPT to write a great application, he jokes, but it’s unlikely you’ll make it through without actually brushing up your language skills.

Don’t come with no startup experience

If you’re thinking of joining Y Combinator, you better have touched the world of startups in some way or other. When looking at candidates’ backgrounds, Dessaigne says that years of experience at a large company and a lack of startup experience will raise some questions. “These are not necessarily the most promising profiles,” he adds. 

Watch out for tar pits

Dessaigne calls bad startup ideas that might look interesting at first “tar pits” in reference to the fact that, from a distance, a puddle of tar might look like water. Come closer, however, and you’ll realise that hundreds of others have tried the same thing without success. 


“If you’re an animal, you’ll head to the tar pit to drink,” says Dessaigne. “But once you get there, you’ll start sinking into it without being able to escape.”

Ultimate tar pits include new social media platforms or travel apps. Or Dessaigne’s favourite: companies that want to help people figure out if clothes fit them when they buy online. “Hundreds of companies have been created to do that. Do you know any that succeeded?” 

Great founders with impressive backgrounds and a bad idea can still make it to YC. The accelerator prides itself on investing in people and teams more than projects. What’s important is the ability to take in feedback and pivot when it becomes clear that an idea isn’t getting anywhere.

“If we invest in these founders — and it happens very often — we bet on the fact that they will change their idea,” says Dessaigne. “The idea really isn’t the most important thing.”

Some ideas are worth fighting for. YC took on Airbnb in 2009 because of how impressive the founders were, says Dessaigne, but no one believed that people would ever be interested in paying to stay at other people’s houses. The founders didn’t pivot — and today, the company is one of YC's biggest success stories.

Daphné Leprince-Ringuet

Daphné Leprince-Ringuet is a reporter for Sifted based in Paris and covering French tech. You can find her on Twitter and LinkedIn