How to Pick a Co-Founder

You've decided to start a business but believe that you'd be (much) better off with co-founders. Not a bad idea, of course. How do you pick the right person? This decision may be the most important of your company's entire history. Most early-stage startups fail due to founder disputes, not the substance of the business. And founders spend so much time together that the business relationship is the closest some of them will ever get to marriage. This is a high-octane, high-consequence, long-term date.

Here are the most important things to look for in your entrepreneurial other half.

1. A complementary temperament. If you tend to run a little hot in a tense moment, get yourself a Cool Hand Luke. If you're the staid type, the ideal partner is likely someone more charismatic. The point is not that oil should seek water or that opposites must attract. The point is instead to find someone who will fill in the gaps around your personality strengths so that employees, partners, and investors will see and benefit from the balance. You'll discover that different people will cotton to each of you, and that pattern will have more to do with the third parties' personalities than anything else. Diversity on your founding team will give you strength.

2. Different operational skills. If you're a product guru, maybe you need a business development or sales-oriented leader to get your vision to market. If you are great at the finances, an early-stage Excel ninja partner probably isn't be the top priority. Even within a discipline there are differences in core operational strengths: often highly technical businesses will have more than one highly technical co-founder, but one of them will, for example, be a terrific architect while the other will be excellent at R&D or engineering. A common tactical error here is for a product- or technology-focused entrepreneur to look for someone with top shelf management consulting experience: it's not a bad instinct, since management consultants are polished and smart, but they rarely have core executive chops apart from project management or some general "operations" background.

3. Similar work habits. You should find someone who shares your expectations on work-life balance. Mismatches on hours or effort quickly and reliably lead to resentments. You don't need to be in the office at exactly the same times, unless for some reason your business actually requires it (as, for example, in a securities trading house). But you do need to share a view as to how much you will work.

4. Self-sufficiency. Your co-founder isn't like any other colleague or employee. She must be fully reliable and self-sufficient, someone who functions on auto-pilot with virtually no input from you. Of course, this is the ideal description of any person at your company. But for a co-founder this is an absolute requirement.

5. A history of working together. If possible, it's best to work with someone you've known for a while or with whom you've collaborated before. Easy familiarity helps conversations move quickly and allows trustworthy cooperation. This does not mean you need to work with your best friend of many years. Doing so presents its own risks. But a long-term relationship can help you leapfrog the learning curve of the close collaboration, which can sometimes take years to develop. That means that selecting a business school section-mate as your partner just because you're currently in your second MBA year together is an extremely bad idea. There's an important caveat here: in a co-founding relationship, you don't really know the other person till the worm turns. That means you won't see the full color of your partner until something in the business or one of your personal lives goes (very) badly. If you haven't been through the crucible together before, be prepared for what she may be like when you do.

6. Emotional buoyancy. Things always get tough at one stage or another in a startup or small company. There are bad days, bad moments, bad deals, bad quarters, etc. Even if you're a passionate and relentless person, now and again you'll have a tough, "down" day. It's excellent if the things that make you feel low aren't the same as those that get to your partner. As a founder, you can't always show your colleagues when you're having a tough day, but you should be able to show your co-founder, and she should be able to buoy you when needed. Ideally, you'll be there for her when she needs it, because whatever is making her down won't faze you as much.

7. Total honesty. You and your partner must be committed to telling each other the truth all the time, even if it's tough to say or hear. This requires practice and emotional investment. You can't pick a partner who is afraid to tell you what you need to hear.

8. Comfort in her own skin. Insecurity and ego, like fear, can kill your partnership. The best co-founders are those who know themselves well and are comfortable in their own skins. This will save you from having (too frequent) difficult arguments about roles and responsibilities.

9. A personality you like. I'm surprised at how often this one gets missed. At the end of the day, if you don't like your partner, all the other great qualities she possesses won't be enough to sustain you through the long haul of building a business. You're going to spend a lot of time with each other, probably more than you do with your spouses.

10. The same overall vision. Your co-founder should buy into the central vision for the business you are starting. Even after all the many other pieces of the puzzle come together, it is essential that your partner's main motivations for joining your venture include a passion for the project you are pursuing. There are so many reasons a small business or startup won't succeed. A mismatch between the founders' visions should not be one.