7 things you should know about a potential co-founder
10 years ago, I was waiting in line for concessions at a wonderfully nerdy concert: a Lord of the Rings symphony orchestra. The movie played on the big screen while the music was performed live. Glorious.
My wife was 8 months pregnant, and we had a verbal agreement that I could name our daughter after a Lord of the Rings character should she be born that evening. Alas, it took three more weeks for her to arrive, so no baby Eowyn that night.
Who did show up at the Lincoln Center that evening was another young couple. My wife Emily recognized Robyn from a local mom’s group. They greeted each other and introduced us husbands: myself and Robyn’s husband Nathan.
It turned out Nathan was a software engineer at Google, where I had previously worked in business roles. He was a member of a team full of engineers optimizing for “local search” on Google, where the user’s location and other context clues would nudge the search algorithm from the internet’s definitive top-ranked web pages to more localized results for the same query.
Nathan and I both lived nearby each other in New Jersey’s Gold Coast, just across the Hudson River from NYC, so we started getting together to talk tech over hard root beers in Hoboken. We realized we were like-minded with complementary skills, and both interested in building a company from the ground up, so we signed up for "Faith & Entrepreneurship" class together at Redeemer Church. Shout out to Scott Calgaro and Dave Blanchard for teaching us young guys some early business lessons.
We decided to start a business together based on an idea of mine, shooting for the moon as a tech startup connecting real estate investors with capital online. I had spent time outside my day job learning more about real estate tech and interviewing real estate investors, lenders, and brokers about their pain points. It seemed obvious to me that there should be a “Rocket Mortgage for Commercial”, and I was trying to figure out why there wasn’t, and how there could be. It seemed to me that someone would make a billion dollars building upon that idea.
While some peers were impressed by my “Google and Facebook” resume, the truth was I was a 27-year-old first-time founder without much concept of the pitfalls waiting for me. This is How Not to Founder after all.
That said, co-founding with Nathan wasn’t one of those mistakes. Our startup took eight years, had many twists and eventually exited, though not with a jackpot outcome. Despite that, we learned to build something real. I even gave my 8-year-old the middle name Nathan in honor of my co-founder.
I use the word “fortunate” because, in hindsight, there’s a lot more I’d want to confirm about a person before committing to a co-founder or business partner relationship. Seven key areas, in fact.
Here’s my framework and accumulated interview questions for canvassing a business partner as critical as a co-founder. I provide a link to a Google Doc version at the end that you can grab, copy, and customize for your own co-founder interviews.
1. Startup mental model awareness
Evaluate the candidate’s understanding of startup dynamics, particularly if they are a first-time founder.
Key Question:
What’s the difference between a startup and a small business?
Wrong answers: Technology; margins; size; age.
Better Answer: Desire to grow.
Right Answer: It’s all about the aspiration and potential to scale.
Follow-up: Ask, “Why and how could this startup scale? What might be the biggest challenges we’ll face?”
Additional Questions:
How much capital do you think this business needs?
Besides revenue, which KPI would most closely correlate to the company’s value?
(Note: Probe further by asking about KPIs tracked in previous roles.)
2. Personality and grit
Understand what makes the candidate tick, and whether they can overcome challenges.
Key Questions:
Favorite youth activities:
If sports: Which sport? Strengths/weaknesses?
If art: What form? What inspired you?
What’s the toughest challenge you’ve faced?
Ask: Why did it matter? How long did it last? Who helped you?
Experience with sacrifice:
Have you ever worked without pay (volunteer, internship, commission-based roles)? Why or why not?
Personality vibe:
If you could pick any two celebrities to represent the brand on day one, who would they be?
3. Leadership and management
Delve into the candidate’s experience as a leader and team builder.
Key Questions:
How many people have you directly hired, and in what roles?
Tell me about your best and worst hires.
Have you ever had to fire someone? Walk me through that.
How would former colleagues describe your leadership style?
Remember: Ask for specific names as references.
4. Functional expertise
Identify their practical capabilities across key business functions.
Instructions:
Ask the candidate to rate their proficiency in areas such as Marketing, Sales, Product, Operations, Finance, and Engineering.
Consider prompting an LLM to generate three challenging questions for their most recent role/title.
Involve a trusted functional leader to conduct an interview and then sync with you on their evaluation of the candidate.
Request real-life examples (writing samples, presentation decks, project plans, etc.) to verify their expertise.
5. Subject matter expertise
While deep industry know-how isn’t always a must, candidates should explain their past work in a way that even a novice understands.
Key Questions:
Can you explain your industry and your company’s role in it as if I were five?
What was your previous company’s competitive advantage?
If deeper expertise is crucial, have an industry specialist verify their know-how.
6. Startup readiness/compatibility
This is where I’ll defer to 10 Questions to Discuss with a Potential Co-founder | Y Combinator. They’ve done a great job crafting these questions and some other co-founder resources, including one of the only worthwhile online co-founder matching platforms I’ve seen.
Personal Motivation: Why do you want to do this startup? Outline your financial and non-financial goals.
Roles & Responsibilities: What will our roles and titles be? Who’s taking the helm as CEO?
Equity Split: How should equity be divided?
Location & Logistics: Where will the company be based? Will we be co-located or working remotely?
Idea Flexibility: Are you open to pivoting if the original idea doesn’t work?
Commitment Level: What needs to occur for you to shift to full-time, and can you manage without a salary for a while? What’s your runway? Will you invest personally?
Work Schedule: What are your expectations regarding workdays and hours? Are there any personal priorities we need to accommodate?
Team Building: If we scale, what values should guide our hiring process?
Dispute Resolution: How will we handle major disagreements, or, if things don’t work out, part ways gracefully?
7. Worldview
Explore their underlying beliefs. These could influence business decisions as well as the long-term dynamic of the relationship. You spend a LOT of time and mental energy with a co-founder or business partner. The founders are the spiritual leaders of the team.
Questions:
Why does the world exist?
What’s one belief you hold that sets you apart from your friends and family?
What company values would be most important to you?
Conclusion
Finding the right co-founder or early business partner can sometimes feel like being in the right place at the right time (like a concession line at a concert). But a big chunk of success lies in asking deliberate questions to gauge not just skill sets but worldview, grit, and alignment.
I know this is a lot. Getting to know a co-founder is like dating; it can’t be compressed down to a simple interview. This is a framework, and the real process will take time and effort.
If you’ve laid out an interview or questionnaire for your own co-founder search, reply to this newsletter and let me know. I’d love to compare the questions you ask to mine. We’re all learning how not to founder together, one conversation at a time.