How to interview a technical co-founder

My advice: Ignore all points except the last one. I've seen a lot of startups trying to hire a technical co-founder on their own, even following advice similar to point 1-5, but still ending up with a co-founder that was a bad technical fit ~80% of the time. With the involvement of a technical person in the interview process, usually either referring the candidate or having an additional technical interview with them, that figure drops down to ~20%.

The opinion of your trusted friend or acquaintance is often just as illusory as your ability to judge for yourself. After all, you aren't subjecting your buddy to the same rigor you would a candidate, and you are just as incapable of judging their actual ability as the candidate's. You may trust your friend to give you good feedback, but if your friend is inexperienced or in a completely different technical domain (therefore lacking context), their opinion can even be counterproductive.

And how are you selecting your friend? How many tech people do you really know? Surely not that many if you're non-technical and interviewing for the position instead of partnering with one of them.

Time and again I see founders choose poor technical cofounders. Often it's enough to get the business off the ground, but then as the company grows they fail to grow with it. Now they're a CTO without the ability to handle strategy or manage people.

The sub-optimal recourse in these cases is often to hire a VPE to manage people while the CTO acts like the principal engineer. Now the VP reports to a CTO who is incapable of doing that job and (privately) insecure about it.

Basically I'm saying a non-technical founder selecting a technical cofounder is a crapshoot and people don't answer enough uncomfortable questions up front. Management skills (or at least aptitude) should be part of the selection criteria. There should be a discussion up front about how the position will evolve over time, and what the success criteria are at each stage, and what happens if those aren't met (mentoring, career counseling, step into new role with reduced title)? And the same conversation should happen in reverse, from the CTO to the CEO.

nice article, though:

> A non-technical founder interviewing a technical one is akin to a brain surgeon hiring a rocket scientist. Forgive the self-aggrandisement!

It's not self-aggrandisement but lacks acknowledgement that it's equally complex the other way around. As engineers we tend to think no aspect is more important than the product we build. Yet without the right person to understand financial growth (and the patience to carry us along despite our lack of understanding), it's going to be rough! (not just finance, but sales, marketing, even legal depending on the field).

For finding a technical co-founder, I think this is more like it:

Imagine you are looking for someone to marry and to cook for you. You will have to get along with them for years. You will need to share intimate secrets with them. The main thing that is really different is that you will not be having sex with them (although from what I hear that is not actually very different from most marriages).

The other thing is that instead of cooking food, they are doing engineering research. Pretty much all software projects are complex research projects. Now, imagine if the woman you married were a bad cook. You could always go out for takeout after dinner lots of the time. But say your entire business was built on making sure that her eggplant soufflé or whatever was 100% on point. If it doesn't taste good, it just crashes and you can't make money. But this is not eggplant soufflé its a completely new dish you need her to invent as a master chef. Only its more complicated than that. It has a thousand moving parts. Its sort of like they are inventing a new type of space ship for you.

So anyway, I would try to do smaller test projects or subprojects with people first and be very careful making a selection of a partner. Ideally it would take several months or a few years, checking out multiple people.

Also be aware that about 50% of all marriages end in divorce.

I mostly agree. A co-founder interview should be more of a conversation rather than a traditional "company vs. employee" interview. Nevertheless, if it is already a running project, there is an imbalance of trust and skin in the game, similar to a job interview. So going through a technical screening can be a very easy way for the candidate to close that trust gap.

Also, the popular perception between technical co-founder and early employee-CTO is very blurry (unless you go by virtual vs. real shares). Some people will call a CTO that joined 3 months into the project and holds 10% virtual shares a co-founder and some people won't. Same goes for "technical co-founder" vs. "early CTO" interviews.