You can start a really successful company as a solo founder, but it's hard. Having a co-founder helps you share tasks and the emotional burden of starting a company.

Among YC companies valued over a hundred million, about half of the co-founding teams met in school, primarily during their undergraduate years.

About 20% of co-founding teams in top YC companies met at work, while 16% were introduced by mutual friends.

For female founders in YC, 33% of co-founding teams met at school, 20% at work, and just under 10% at events.

The easiest way to meet a potential co-founder is through school or work, as you have context and can observe their performance over time. It's important to assess how well you work together as a team and how effectively you communicate.

Y Combinator prefers well-balanced teams that can both build and sell their product, and communicate clearly about what they are creating.

YC looks for teams that have collaborated for some time, as this indicates a stronger commitment and likelihood of sticking together long-term.

Ideally, co-founders should have developed the idea together and worked on building the product from the start, but even if one co-founder joined later, an even equity split is still preferred.

Given that the average time to IPO or exit is about 8 to 10 years, it's crucial that all co-founders feel equally invested and are prepared to work full-time for that duration.

If you're not willing to offer a potential co-founder equal equity, you should reconsider if that person is the right fit for your team.

94% of the top Y Combinator companies have co-founders, and they typically meet at school or work; an equal equity split is highly valued in these partnerships.