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100 Questions to Ask Your Future Technical Co-Founder

You finally got a meeting with a potential technical co-founder. You like their background. You think there might be something here. Now what?

Solo founders ask me this question more than almost any other: “I’m meeting with a potential technical co-founder. What should I actually ask them?”

They’ve done the work to get in the room. They’ve networked, posted, asked for intros, maybe joined a community or two. The process of finding candidates matters. But it matters far less than what happens when you’re actually sitting across from someone.

These are the same questions I worked through with my co-founder Amy Lin before we started Outcast Ventures. Not a casual “let’s grab coffee and see if we vibe.” Hours of conversation over months. Who makes the final call on what? What we look like at our worst? What would make us resent each other?

The hard questions most people avoid until things start breaking.

The best founding teams I’ve backed did this early. Dylan Field and Evan Wallace spent weeks on decision rights before writing a line of code at Figma—who owned product direction, who had final say on hiring, what happens when they disagree.

They documented it.

Chris Britt and Ryan King at Chime did the same: who owned engineering, who was the face of the company, how they’d handle a fundamental disagreement about direction. They also shared similar risk profiles, something founders often overlook. If one person has a mortgage and dependents and the other has nothing to lose, you’re not taking the same bet. Life stage and financial runway always surface eventually, and when risk isn’t aligned, resentment builds quietly, then all at once.

After two decades of recruiting and evaluating technical talent, here’s what I’ve learned: skills can be developed.

Mindsets are nearly impossible to shift.

That’s why these questions are organized from the inside out to surface who someone is, how you’ll work together, and only then what they can do.

How to Use This List

The order matters.

Most founders start out asking about technical skills, architecture opinions, past projects. That’s backwards. You can teach someone a new framework. You can’t teach them to handle pressure differently or want the same things you want.

These 100 questions are organized in three layers:

1. The Individual (Questions 1-50) Who is this person at their core? Their psychology, values, risk tolerance, ambition, how they handle adversity. This is the foundation. If there’s misalignment here, nothing else matters. These things don’t change.

2. The Relationship (Questions 51-75) How will you work together? Decision rights, communication, conflict resolution, expectations of each other. This is the operating system you’re designing. Get it wrong and you’ll pay for it every day.

3. The Skills (Questions 76-100) What can they do? Their track record, technical philosophy, how they build. This is what most people ask about first. It should come last. Skills are the most learnable layer.

Don’t ask all 100 in one conversation. That’s an interrogation, not a dialogue. Pick 10-15 that matter most for your specific situation. Start with the early sections. Understand who they are before you evaluate what they can do.

Pay attention to what they ask you. Great technical co-founders are evaluating you just as hard. If they’re not asking tough questions back, that’s a signal.

And remember: the goal isn’t to find someone who gives perfect answers. It’s to find someone whose honest answers you can build with.

Part 1: The Individual

Best Self, Worst Self

You’re not choosing a co-founder at their best. You’re choosing who they are when things get hard. Start here.

When you’re at your best, what does that look like?
When you’re at your worst, what does that look like?
What does a peak energy week look like for you? What drains you?
What would your previous co-workers say is hard about working with you?
Who is the manager or colleague who liked working with you the least? What would they say?
What’s the harshest professional feedback you’ve ever received? What did you do with it?
What’s something you’re actively working on improving about yourself?
What’s your MBTI, Enneagram, or working style assessment? How much does it resonate?

What does a good answer sound like? When I asked a potential co-founder what they look like at their worst, they said “I get quiet and withdraw.” That’s useful—it’s specific, honest, and something you can work with. When another said “I don’t really have a worst self,” I ended the conversation.

Values and Integrity

Values don’t change under pressure. They reveal themselves. Know what someone believes before you need to find out.

What does integrity mean to you?
What’s something you’re not willing to compromise on?
What’s a value you hold that most people would find extreme?
How do you feel about transparency with the team? With investors?
What kind of company culture do you want to build?
How do you make decisions? Gut vs. data?
How do you feel about working with people who are smarter than you in certain areas?
What would make you lose respect for a co-founder?

Risk Profile and Life Stage

If you’re not taking the same bet, you’re not really partners. Mismatched risk tolerance breeds resentment.

How much financial runway do you personally have?
What are your personal financial obligations? Mortgage, dependents, debt?
Do you have a partner or spouse? How do they feel about you doing a startup?
What would you need to earn within 12 months? 24 months?
How do you think about the risk you’re taking relative to your life stage?
What’s the worst financial outcome you could stomach?
Have you ever taken a major financial risk before? What happened?
If this takes five years to pay off, are you okay with that?
How do you feel about equity vs. salary tradeoffs?
What scares you about this opportunity?

Ambition and Vision

You need to want the same thing. Misaligned ambition kills companies slowly, then all at once.

Why startups? Why not stay at [big company]?
What does success look like for you in five years?
What size company do you want to build?
How do you feel about raising venture capital?
What would make you want to quit this?
How long are you willing to work on something before it’s clearly working?
What’s a company you admire? Why?
Do you want to be a CTO long-term or eventually move into something else?
If this fails, what will you think was the reason?

How They Handle Adversity

Startups are years of things going wrong. You’re selecting for someone who won’t break—and who won’t break you.

Tell me about a time everything went wrong. What did you do?
How do you handle working on something for months that might not ship?
What’s the longest you’ve worked on a problem before solving it?
How do you recover when you’ve made a big mistake?
What do you do when you’re stuck?
How do you handle criticism of your work?
Tell me about a conflict with a colleague. How did you resolve it?
What do you do when you’re burned out?
How do you handle ambiguity?
What’s the most unfair situation you’ve dealt with at work? How did you respond?

Working Style

You’ll spend more time with this person than anyone else in your life. Small incompatibilities compound.

What hours do you like to work?
How do you feel about remote vs. in-person?
What does work-life balance mean to you at a startup?
How do you stay focused? What breaks your focus?
How do you prefer to communicate? Slack, calls, in-person?

Part 2: The Relationship

The Co-Founder Dynamic

This is the operating system for your partnership. Ambiguity here will cost you later.

Why are you interested in working with me specifically?
What concerns do you have about me as a co-founder?
What do you think I bring that you don’t?
What would you need from me to do your best work?
How should we divide responsibilities? Who makes the final call on product? On engineering? On hiring?
How do we handle it if one of us wants to leave?
What does a good co-founder relationship look like to you?
How do you want to handle disagreements?
What’s a dealbreaker for you in a co-founder?
Have you had a co-founder before? What did you learn?
How do you envision we make time for the co-founder relationship outside the day-to-day?
If we need to bring on a third co-founder or key executive, who has final say?
What’s your ideal equity split? Why?
What would make you resent me?
What’s something you need me to know before we commit to this?

Working With Non-Technical People

This is the co-founder relationship in miniature. How they work with you specifically matters more than how they work in general.

How do you explain technical constraints to someone non-technical?
Tell me about a time you disagreed with a product decision. What happened?
How do you handle being asked “how hard would it be to…”?
What’s the worst miscommunication you’ve had with a non-technical colleague?
How do you want me to give you feedback on technical work?
How do you prefer I communicate changing priorities or direction?
How should we make decisions when we disagree?
What’s something non-technical co-founders often get wrong?
How do you feel about me sitting next to you while you debug something?
What’s the best working relationship you’ve had with a non-technical partner? What made it work?

Part 3: The Skills

Their Track Record

Past behavior predicts future behavior. The stories they tell—and how they tell them—reveal patterns you’ll live with.

What’s the hardest problem you’ve solved? Walk me through it.
Tell me about something you built that you’re proud of.
Tell me about something you built that failed. What did you learn?
What did you learn at [previous company] that you’d bring here?
Why did you leave your last role?
What would your previous manager say is your biggest weakness?
Have you ever had to fire someone or manage someone out? What happened?
What’s the largest team you’ve managed? What did you learn?
Tell me about a time you missed a deadline badly. What went wrong?
What’s the most pressure you’ve been under? How did you handle it?
Have you ever had to pivot or kill a product? How did you decide?
What’s a mistake you’ve made more than once?

Their Technical Philosophy

How someone thinks about technology tells you how they’ll make the hundreds of decisions you won’t be in the room for.

What’s a technology decision you made that you’d make differently today?
When do you reach for a new framework vs. sticking with something boring?
How do you decide when to build vs. buy vs. integrate?
What’s your philosophy on technical debt? When is it acceptable?
Describe a time you over-engineered something. What did you learn?
What’s an unpopular technical opinion you hold?
How do you think about security from day one vs. bolting it on later?
How do you balance shipping fast vs. shipping right?
What technology are you most excited about right now? Why?

How They Build

Skills can be learned. But how someone approaches building—their craft, their process—reveals discipline and taste.

Walk me through how you’d architect [our specific product idea].
What’s the smallest version of this we could ship to learn something?
How do you decide what to build first?
What’s the process for estimating how long something will take?

What Comes Next

These 100 questions will tell you a lot about your potential co-founder. But they won’t tell you everything.

What do the people who’ve worked with them say when they’re not in the room? And just as important: what questions should you be asking yourself before you even start this search?

That’s the next piece in this series.

We’re publishing this series as we build out Catalyst, Outcast’s co-founder matching program. Subscribe to follow along.

This is the first in a series on co-founder selection from Outcast Ventures. Subscribe to our newsletter to be notified of the next one.