• As startup activity rises in the US, founders face a crucial early decision: who to build with.
• BI asked three sets of cofounders how they built strong relationships and how they’d handle a split.
• They shared which conversations to have early, before avoiding them becomes costly.

You’ve been imagining this moment for a while. Maybe spent weeks having long, potentially tough conversations in preparation. Now, it’s finally time to pop the question:

“Will you be my cofounder?”

Interest in entrepreneurship appears to be rising in the US, with new business applications already up by more than 450,000 in the first half of 2026 compared with the same period last year, according to the US Census Bureau.

If a founder’s startup feels like their baby, their cofounder may very well feel like a spouse. Once they’ve chosen that special someone, setting the right guardrails for that partnership is crucial. In some ways, AI has made these decisions even more important as business teams get smaller, companies move faster, and the pressure becomes more concentrated.

Business Insider asked three sets of AI startup cofounders what early conversations have led to successful partnerships, and how they determined who gets what if things go wrong. They shared the key elements of their early agreements, along with what they’d put in their ideal “cofounder prenup.” Their words have been edited for length and clarity.

Agree on what being committed means for you

David Emelianov is a 32-year-old software engineer and entrepreneur, based in the Bay Area. He and his cofounder, Jordan Gaston, sold their app, Trimbox, for $4 million at the end of 2025.

I think there are three conversations every cofounder should have before writing a single line of code: What kind of company are you actually trying to build, what level of commitment does everyone expect, and what happens if someone wants out.

Sit down and decide if you’re trying to build a venture-backed, winner-take-all company where the goal is to swing for the fences, or if you want to build a profitable bootstrapped business that throws off cash. Neither answer is right or wrong, but they’re very different games.

If one founder is optimizing for a $20M acquisition and the other wants to build a 30-year company, you’re going to run into problems eventually.

The second conversation, though, has become especially important for me over time. Earlier in my career, I would have assumed everyone should be 100% focused on one company. Today I think differently. I work on multiple projects at once, and I actually think that makes me a better entrepreneur because ideas, lessons, and opportunities transfer between businesses.

The important thing isn’t that everyone works the same way; it’s that everyone agrees on what “committed” actually means. Is it OK to have side projects? Consulting? Angel investing? Starting another company? Those expectations should be crystal clear from day one.

If I had to pick just one conversation to have, though, it’d be the first one. You have to make sure you’re playing the same game before it begins.

Define different exit scenarios early

Shalini Aggarwal is a 50-year-old CEO in San Jose, California, and Andy Ratsirarson is a 37-year-old CTO. The two left Amazon at different times and reconnected as cofounders of Tenfali, an AI startup.

We believe a cofounder prenup should include the things that are easy to ignore when everyone is excited about an idea. This includes equity split, vesting schedule, IP ownership, roles and responsibilities, how major decisions get made together, and, importantly, what happens if someone leaves.

You need to have an honest conversation about expectations before things get hard, and find out what happens if one founder can no longer give the company the same level of commitment.

For example, what happens if there is an acquisition offer, if one founder wants to keep going, and the other does not? The goal is not to assume the relationship will fail, but to protect the company and the relationship by making the hard conversations explicit before emotions and money are involved.

You also need a shared framework for resolving problems, because conflict is inevitable in a startup. Customers may be slow to convert, the product may need to change, or money may get tight. In those moments, the question is not whether you will disagree, but how you will make decisions when you do.

Once both founders are aligned on a decision, there cannot be a blame game later. It becomes a shared decision, and both people have to own the outcome. Those conversations can feel uncomfortable early, but they are much harder to have later.

Decide whose call is final …

Praneet Dutta is a 32-year-old CEO and cofounder at AI startup Pomo. He’s based in Palo Alto.

A cofounder prenup, for me and my cofounder Joe, is about what happens in the 30 minutes after we both think we’re right and disagree on how to move forward. We had it come down to three understandings.

First, we need clear, previously established domain ownership. Whose call is final in which domain? Without that, the company can get stuck waiting for a consensus that isn’t coming.

Secondly, significant decisions get a real conversation, in person or on a call, never a chat thread. Tone and context matter most when the stakes are high. That rule got tested early. When our seed round ended up oversubscribed, deciding how to build the cap table meant a series of live conversations with each other and with friends who had advised us. I cannot imagine having done that over chat.

Third, we built a habit of revisiting the agreement. The arrangement that works for a six-person team will not automatically work later. So we treat it as a living agreement, not a signed-once document.

The real cofounder risk is fake agreement, not conflict. That was the biggest shift for us. We stopped treating disagreement as something that threatens the relationship and started treating unclear disagreements as what threatens the company.

Determine how you stay on the same page while moving quickly

Joe Cheuk is a 33-year-old CTO and cofounder, based in Seattle. He cofounded the AI startup Pomo with Praneet Dutta.

Praneet and I both like to move fast. Velocity is one of our biggest advantages as a small team, but two people moving fast in slightly different directions compound quickly. I’d add the clause people skip: determine how you stay aligned at speed.

In a large company, the landscape shifts, and you usually have quarters to adapt. At an AI startup, the tools, the models, and sometimes the customer expectations change month to month. The hardest part was not any single decision. It was learning to make good decisions and give a six-person team confident direction in an environment where last quarter’s playbook may already be outdated.

So agreeing early on how we steer the ship together was one of the most important things we did. Ours is simple: either of us can ask to sleep on a big decision, we each lay out our full viewpoint before we decide, and once a call is made, we both own it and keep moving.

That is the part that founders underestimate. Most cofounder issues do not start as explosions. They start as tiny moments where both people choose silence. Making these conversations normal before they become expensive is one of the highest-ROI things cofounders can do.

Do you have a similar story to share? If so, please reach out to the reporter at aapplegate@businessinsider.com.