Founders face lots of hard problems at the earliest stages—building an MVP, finding users, finding investors—but finding a co-founder can be uniquely difficult. Even if you have a strong network, your friends may not be startup-oriented, and the ones who are may not be available on the same schedule you are [1]. And if you don’t have a strong existing network, the search is even harder.

Of course, you don’t need a co-founder to start a company. Many successful startups have started without one, including 4 of the top 100 YC companies. YC does fund solo founders—over 10% of companies in recent batches. But starting a startup is hard, to put it mildly. For most founders, we recommend finding someone to work with and share that burden.

YC’s advice has historically been to find a co-founder through your existing network. That’s still good advice—co-founder relationships with someone you’ve known and worked with for years will have a lower attrition rate than a relationship with someone you just met on the internet. (At least one would expect so! We’re going to track data on this.) But for many members of the Startup School community, that isn’t an option. As the internet has increased access to information about startups, we’re seeing lots of new founders who live outside traditional startup hubs (or college towns) and/or don’t have a deep existing network to plumb.

The difficulty new founders face in finding a co-founder is reflected in the data. Of over 100,000 active founders in Startup School, 20% say they’re still looking for a co-founder. Of 60,000 aspiring founders who haven’t started a company yet, about a third mention “I haven’t found the right co-founder” as a reason they haven’t started (second only to “I’m not sure what to work on”).

Since Startup School is too large for us to be able to work with founders individually the way we do in YC’s core program, we rely heavily on software and especially on building systems to help community members support each other. Building a marketplace to help find a co-founder felt like a natural next step. We're hoping that a dedicated marketplace will be more effective than the alternatives many founders resort to right now, like trawling Twitter and LinkedIn. Since everyone using the service is actively looking for a co-founder right now, the hit rate should be higher. We’ve added the kinds of filters most relevant to co-founding (time commitment, location/timezone, division of responsibilities, etc). Finally, we took inspiration from modern dating apps to make the experience as seamless as possible and let founders review hundreds of potential matches quickly. To the extent that finding a co-founder is a numbers game, we want to make it as easy as possible to review many profiles quickly.

We soft-launched this product to the Startup School community in January, and so far have facilitated over 9000 initial matches among 4500 founders. Many of those matches have gone on to work together on trial projects and even form startups. Two of those startups have made it into the latest YC Core batch (S21). We’re hoping that there will be many more over time!

You can find out more and sign up at https://www.startupschool.org/cofounder-matching. This is still the beginning and I expect we’ll be learning and changing a lot as we go, but I’m excited to share this tool with you all. I’d also love to hear from all of you on what has (or hasn’t) worked for finding a co-founder, since I know many of you have gone though this exact process!

[1] Timing may be one reason why it’s easier for university students to find potential co-founders: everyone finishes class at the same time, so it’s easy to all agree to try a startup for the summer.