30 questions to ask a potential co-founder before you commit

Most co-founder conversations stay in the comfortable zone: the idea, the market, the plan. The questions below live in the uncomfortable zone, which is exactly where partnerships succeed or fail.

You don't need to run these as an interrogation. Spread them across a few honest conversations. What matters is that every one of them gets answered before equity does. And answer them yourself too, the point is comparing answers, not grading theirs.

Vision and ambition

The most expensive misalignments are here, because they can stay hidden for years.

1. What does success look like for you in five years: a company you run forever, or an exit?
2. Would you take venture capital if it were offered? Would you be disappointed if we never raised?
3. If someone offered to buy us for a life-changing-but-not-huge amount in year two, what's your instinct?
4. What would make you walk away from this?
5. Why this problem, what's your honest connection to it?

Commitment and time

6. When would you go full-time, and what has to be true first?
7. How many hours a week can you genuinely give this right now, not aspirationally, actually?
8. What else competes for your time (job, family, other projects), and how do you plan around it?
9. How long is your personal runway, how many months can you work for little or nothing?
10. If this takes four years to get anywhere, are you in?

Money and equity

If you can't talk about money comfortably now, you won't survive talking about it under pressure.

11. What salary do you need to survive, and when do you need it by?
12. How should we split equity, and why? (Read how to think about the split first.)
13. How do you feel about vesting with a one-year cliff, for both of us?
14. Would you put your own money in? How would you feel if I did or didn't?
15. What financial situation would force you out?

Roles and decisions

16. Who does what, and where do our skills overlap enough to cause friction?
17. Who has the final call on product? On hiring? On spending?
18. What happens when we flatly disagree on something important?
19. Who should be CEO, and what does that title mean to you?
20. What work do you hate doing? (Someone has to do it, better to know now.)

Working style and pressure

You're evaluating the person who shows up in month nine, not the one at this table.

21. What does your worst week look like, how do you behave when things go badly?
22. How do you want to receive hard feedback? How do you deliver it?
23. Tell me about a working relationship that went wrong. What happened, honestly?
24. What's your communication default when you're struggling, talk, or go quiet?
25. What would previous colleagues say is the hardest thing about working with you?

The relationship itself

26. What happens if one of us wants to leave in a year? Walk the scenario.
27. What happens if one of us isn't pulling their weight, how should the other raise it?
28. Is there anything in your life (legal, financial, personal) that could blindside this company?
29. What do you need from me that you're worried you won't get?
30. What question were you hoping I wouldn't ask?

How to actually use these

Three practical notes:

Write answers down. Memory is generous; notes aren't. Six months in, "you said you'd go full-time after the MVP" is a fact-check, not a fight, if it's written somewhere both of you saw.

Both answer everything. A question you'd hesitate to answer yourself is a question you can't fairly ask. Sealed, simultaneous answers beat live ones, the second person to speak always adjusts, usually without noticing.

Answers matter less than reactions. Someone who engages with "what if you're not pulling your weight?" openly is showing you how they'll handle real conflict. Someone who deflects, jokes it away, or gets defensive is also showing you, and that signal is usually visible right at the start.

Inside Cofounnder, this exact process is built in: interviews where you pick the areas that matter, both founders answer every question, and answers stay sealed until both have submitted, then unlock side by side. However you run it, run it. The questions are only awkward now; unasked, they're expensive later.