Y Combinator runs a website where we help people find potential co-founders.

While running that, we’ve had a lot of people ask for a set of questions to help figure out whether they’re a good match with a potential co-founder.

We’ve compiled a list of the 10 questions that we think are the most important ones to answer.  The best time to go through these is after you’ve gotten to know someone, have found an idea you’re both interested in working on, and are deciding if you’re ready to commit to working together.

We’ve split this document into two sections: the 10 most important questions to discuss before deciding to work together, and other questions that will help you get to know each other.  We also included a checklist of things to do when bringing on a co-founder.

Note that no questionnaire can be a substitute for actually spending a lot of time together in person to determine if you like working together and get along well in practice. That’s the only way to know if you’re actually compatible with someone, and it usually takes several months to know for sure. This questionnaire is designed to supplement that, not replace it. Here's the Google Doc version of this questionnaire if you'd like to use it as a template.

10 key questions to discuss before deciding to work together

We derived these 10 questions by talking to many teams who met on YC’s co-founder matching, and by looking at the most common reasons founding teams break up.  

For a lot of these, you may not know the answer yet or may not have a strong opinion. That’s fine! Most things in startups you figure out as you go.

The goal here is to detect situations where you might have strong differences, so you can discuss them early, rather than being caught unawares later on.

The best way to go through this is for each founder to copy this document, write answers independently, then share your answers and discuss.

1. Why do you want to do this startup?  What are your personal goals here, both financial and non-financial?
2. What will our roles and titles be? How will we divide responsibilities? Who will be CEO?
   Roles inevitably change a lot over time, but you should have a plan for what you’ll each work on for the first 6-12 months, and decide on who will be the CEO (and what the CEO’s responsibilities are).
3. How will we split up equity?
   It’s important to resolve this one early. This section of the co-founder matching manual may help.
4. Where will the company be based? Where will we each live? Will we work together in-person or remotely?
5. What idea will we work on? If that idea doesn’t work out, are you willing to change the idea? Are you only interested in working on ideas in certain areas?
6. What needs to happen for each of us to go full-time (quit other jobs or school commitments)?
   I.e., We’d have to raise at least $xx from investors, we’d need to validate the idea with a paying customer, we’ll do it if we’re enjoying working together in two months. Obviously, this is N/A if you are both full-time already.
7. What is your personal financial situation? Are you willing to work for free and live on your savings? For how long? If you'll need a salary to work on this full-time (either now or at some point), how much do you need to feel comfortable?  Will either of us put money into the company?
8. What will our typical working schedule be (what days we work, what hours / day, etc)?  How long do we want to keep that up?  Are there any things outside of work that are important to you to make time for?
9. If we are successful enough to get to build a team of employees, are there things that are important to you about how we do that?  I.e., building an in-person vs remote company, having certain cultural values, having a particular approach to hiring or managing people?
   It’s fine if you don’t have strong opinions on this yet.
10. What will we do if we’re having trouble agreeing on an important decision?  What will happen if we decide we don’t want to work together anymore?

Questions to get to know each other better

These are questions that are designed to teach you things about each other that are important for having a good relationship.  These are good ones to go through once you’ve decided that working together makes sense.

• How would your friends or colleagues describe your strengths and weaknesses?
• What are you proud of having accomplished (can be work-related or not)?
• What do you do with your free time?  What are your hobbies and interests?
  One of the surprising things about successful co-founders is how consistently they have overlapping outside-of-work interests.
• What are companies, founders, or products you really admire - especially ones that you want to model this company after?
• What were your experiences like at your past jobs or past startups? What did you like and not like about how the companies were run? What lessons did you take away?
• What is your life story and how have your experiences shaped your values?
• Have you worked with a co-founder previously?  What was that experience like?
• What kind of work is so fun for you it doesn’t feel like work? What kind of work do you avoid doing?
• What are your long-term goals in life?  What is your overall life plan and how does this startup fit into it?
• What makes you most excited about working with me?
• What makes you concerned about working with me?
• What environment do you work best in?  What can we do to help you create it?
• What’s the best way for me to give you feedback?
• When you feel stressed, do you tend to want to talk about what’s going on or avoid talking about it?
  Psychologist and founder coach Amy Buechler wrote an excellent article on this and how these two styles affect co-founder relationships.
• Are there pressures in your life that you’re dealing with now?
  Often pressures or challenges in your life create pressure on your startup.  If you’re dealing with a family issue, a visa / immigration issue, a health issue, etc., you should really tell your co-founder because it’s important for them to know what’s going on.

Checklist of things to do when bringing on a co-founder

Ok, you’ve gone through the questionnaire and everything seems promising. Great!  Here are some related things you’ll want to do.

Before deciding to work together:

☐ Meet in person and do a trial project.

☐ Do reference calls on each other. Ask people who have worked with your potential co-founder what it was like working with them, and for advice on how to work with them effectively. It’s best if you do this transparently – agree on when you are ready to take this step and then swap suggested references.

☐ Given how important this person is going to be in your life, if you have a spouse or a serious relationship, you should have your significant other meet your co-founder.

After deciding to work together:

☐ Create a system to prioritize tasks and decide what to work on.
This is a great post on one such system. You don’t have to adopt this one, but it’s important to have some system.

☐ Set up a recurring 1-1 with each other (typically once a week) to talk specifically about how things are going with working together.
This concept was created by Amy Buechler, who named them “Founder syncs”. She wrote a detailed guide to how to run them.  Done correctly, these can really help avoid co-founder breakups.


Here's the Google Doc version of this questionnaire if you'd like to use it as a template.