How to know if it’s a good Co-Founder Match

by Joan DeGennaro5/10/2023

Whalesync Co-Founders Matthew Busel and Curtis Fonger with the text "How to know if It's a Good Co-founder Match"

Curtis Fonger and Matthew Busel met on YC’s Co-Founder Matching (CFM) Platform, a tool we built to help co-founders find each other. Even in early conversations, their fit as co-founders was clear to each of them. With both eager to build, work began on Whalesync — which helps businesses sync their data across no-code tools like Airtable and Webflow — before the two even met in person. YC invested in Whalesync in the Summer 2021 batch.

“Without this we never would have met, done YC, or started this company.” - Curtis Fonger

We talked with Curtis and Matthew about how they utilized the CFM platform in their co-founder search, and how each determined the other was the right person to start a company with. Their process is a great example for anyone looking for a co-founder, including best practices for laying the groundwork of a successful startup and important questions to ask early on.

What brought you to YC’s Co-Founder Matching Platform?

Curtis: I was at Google and had been looking for a co-founder for quite a while, mostly among people I had worked with closely in the past. They all had reasons to not do a startup. I was so determined to do a startup again though that I decided I would just do it alone. I started [going through YC's] Startup School –  watching the videos and sharing weekly progress on ideas. When YC announced the beta launch of Co-Founder Matching, I signed up. I figured if YC was doing it, it was worth a shot.

Matthew: I had been a PM for about four years and always wanted to start a company. I quit my job and went full force – experimenting with a bunch of ideas. I’d rather have a co-founder than do it alone and had a full pipeline with people from my network and other startup communities. When I saw the YC CFM beta, I signed up and was quickly impressed with the quality of talent.

What was your process for evaluating co-founders?

Curtis: I met a bunch of people quickly, including Matthew. I kept the initial video call casual – solely using the time to get to know the person. At the end, I’d mention [Gloria Lin's] 50 Questions and ask them to complete it offline so we could review it together on the next call.

Very few people actually completed it, showing me they weren’t serious about finding a co-founder. Of those people who did complete it, I’d find we weren’t aligned on critical areas. When I met Matthew, I couldn’t believe it; it was like ‘where’ve you been all my life?!’ We got along so well, had a very similar mindset, a similar vision for where we wanted to take a company, and similar values. I was amazed.

Matthew: We each filled out the 50 questions from Gloria Lin’s Founder Dating Playbook, which made it clear how aligned we were in values and desired trajectory. Some specific things we were highly aligned on were:

  • Team culture: We both wanted to build a fun, collaborative, and focused culture.
  • Personal attitude: We were both “students of the game” who had been constantly trying to refine our skills, learning as much as possible from experts like YC. We each had builders’ mentalities and wanted to work with people who knew how to roll up their sleeves.
  • Who we admire: We also had similar attitudes about who we admired. We saw traits like thoughtfulness and empathy as critical and more self-centered attitudes as destructive.
  • Ideal exit / timeframe / commitment: Both of us were in this for the long run. The goal wasn’t to “try this out and see if it works” or quickly flip a company. We were both excited about the prospect of building something meaningful over the course of many years.

Was it uncomfortable to ask someone who is basically a stranger all of these questions and share your answers?

Curtis: The first startup I did, we didn't have this list of questions. We didn't know what topics would be critical down the road and what would be better to discuss up-front. When things like fundraising, hiring, finances, etc. came up later, it was more difficult to have those conversations because we were in the middle of stressful situations.

This time around, I didn’t care how uncomfortable it was, I knew I was going to avoid that.

What were some good questions to weed people out?

Matthew: Equity split. Ideal company exit, which helped me determine who actually wants to build a venture-backed business. The commitment and finance pieces were important to me to be aligned on from the get-go.

Curtis: How do you deal with conflict? Name a time you did it well and a time you didn’t. Logistical things like roles, compensation, and equity.

What solidified your partnership with one another?

Matthew: We hit it off for the same list of reasons Curtis mentioned. And we were in the same boat mentally - we were both ready to go. We started a 6-week trial project together (here’s the 1-page doc that outlines the scope of the project). During the trial, we really just tried to simulate what it would be like if we were actually working on a startup together.

We didn’t come up with a fake business school-type project. Instead, we just did what we’d been taught by YC to do: talked to customers (user research) and built product (early designs/prototypes). While it was [initially set as] a 6 week trial period, after 4 weeks it was going so well that we decided to start formalizing the partnership early. As a final step, we did reference checks with people who had worked with the other person before.

Other than the questionnaire and working well together, were there any other areas where you were weirdly aligned?

Matthew: I really appreciated how honest he was about his weaknesses. He didn’t try to hide unpleasant traits or situations, which made me trust him immediately. I also appreciated how he approached the equity split. Based on his background, he’s more senior than me. He could have pushed for a 60/40 split, and I would have taken it. But he wanted a 50/50 equity split for the health of the business, and I loved that he was thinking about it that way.

Any other best practices you’d recommend to co-founders who are on the search?

Curtis: Really early on, we started a weekly [retrospective]. If anything is bothering us, we have to bring it up in the meeting. We agree to be open, honest, and understanding. So, if we don’t talk about it during that meeting, we’re breaking the rules! We rarely have anything bothering us, but if we did, we have this depressurization mechanism that we set up right from the start.

Matthew: We also sat at a whiteboard and outlined all the elements of the business and who gets the final say if we find ourselves in a stalemate. We’ve never reached that point, but it’s nice to have. For example, if we ever disagreed on fundraising, Curtis gets the final say. If it’s about the product, it’s mine.

Curtis: And that came directly from one of Kevin Hale’s talks! It is really good advice to do this ahead of time. Really, ALL the advice is right there in front of you in Startup School.

Are there any other advantages you have as a company for having met on Co-Founder Matching?

Matthew: You gain a whole new network when you meet someone outside of your community. My network grew to include Curtis’ and vice versa. All of Whalesync’s early hires came from his network.

The YC batch is sometimes described as a "pressure cooker" for teams. You had met more recently than most teams, so how did it go? Can you share a moment where you remember working really well together?

Matthew: While we met online and we’re now a fully remote company, we worked together in person during YC. This was really helpful to accelerate a lot of the early-day information sharing that is so important.

Toward the end of the batch, there was a moment when it became clear we weren’t going to hit our ambitious Demo Day goal. I was pretty upset and questioning whether we needed to pivot. Curtis being the incredibly perceptive and thoughtful person he is, pulled me aside and said “let’s go grab a beer”. We sat down and talked about why we were building this product and the vision we had for the company. Despite not hitting our Demo Day goal, we realized we still had very strong conviction in what we were building and where we could take Whalesync.

Going through the YC “pressure cooker” together helped produce moments like that where it became obvious we’d have each other's backs through the highs and the lows.

What has your company been like since going through YC?

Curtis: Things have been going really well. I can’t believe how great Matthew is. It’s weird how well we get along. I’ve worked with a bunch of people in my career, and I don't think I've gotten along with anyone as well – not that I'm a super difficult person to work with. We just don’t have a whole lot of problems.

Matthew: We did YC, raised a round, and then rebuilt the product from scratch. We launched again in March 2022 and have been growing our MRR steadily since then. We’ve just tried to follow all of YC’s advice perfectly. We’re building a product that a small number of people love, and then we’ll expand to a larger total addressable market.

Learn more about Whalesync and how they’re helping companies create programmatic SEO pages here, and read their step-by-step guide to find a co-founder here.

Looking for more on this topic? Check out our recently published list of 10 Questions to Discuss with a Potential Co-founder.


  • Joan DeGennaro