A little over six years ago, my step-brother Jake and I were having lunch together in downtown San Francisco. I’d been wrestling with a startup idea.

LendUp Cofounders

A math major, I had spent years at the Grameen Foundation, the World Bank, and then Citi. Jake, the quintessential computer science nerd, was employee #80 at Yahoo!, then a Zynga platform CTO by 29. To put it mildly, we were on pretty different paths.

With trepidation, I shared my idea with Jake: basically, a fintech company that could create greater financial inclusion. He listened, asked a lot of questions and listened some more. He was hooked.

Things moved quickly after that lunch. We entered the YC Winter 2012 batch and LendUp was born.

Looking back, it wasn’t easy. And it still isn’t. As step-brothers, we started out having nothing in common except for the fact that my dad and and Jake’s mom married each other when we were in grade school. So in light of National Siblings day, we asked ourselves: would we take the startup leap together all over again? For us the answer was easy: absolutely. For those thinking about starting a company with a sibling, we humbly offer the following things to consider:

1) Does your sibling share your level of commitment? Let’s start with an easy one: starting a company is scary, and there are many intense moments. Being able to have full confidence that your cofounder is in it with you through thick and thin is really comforting. Siblings are generally good for that, but ask yourselves if you’re both ready for an inevitable roller coaster.

2) Do you trust your sibling with your life (and your company)? Starting a company means being faced with thousands of decisions and endless projects. It’s hard to overstate the importance of having a co-founder that you trust -- in work ethic, decisioning, creativity, and problem solving -- to help you execute and make the tough calls.

3) Are you and your sibling good communicators (with each other)? At any stage, but especially at the early stage, it’s critical that you can be candid in communicating about everything. Nothing’s too big or small, or too personal. And as your company grows, fewer and fewer people will feel comfortable telling you when you’re wrong. So being able to count on your co-founder as a straight shooter is a huge advantage.

4) It’s good to have differences in how you think about work and just life in general. It’s been a real asset to be good and bad at different things (or as a relationship coach might put it: to have a “complementary skill set”). I am emotional and make gut decisions. Jake is hyper pragmatic and thoughtful. If we had met as adults, Jake says we probably wouldn’t have been fast friends, and that’s okay. Encourage each other to be their genuine self at work as well as at home.

5) Similarly, it’s okay, and might even work in your favor, to come from different career and education backgrounds. Jake has been in two Silicon Valley rocketships -- Yahoo!, and Zynga, which was the fastest billion-dollar revenue startup in Silicon Valley at the time. I worked at very small startups, nonprofits, the world’s largest bank, and an international government agency. This means we bring a lot to the table from a pretty diverse set of experiences -- we’ve seen a lot go well, go wrong and go horribly wrong. Again, having trust here to be able to talk freely and openly is really important.

6) Do you share the same values? Jake is a vegan and I’ve never refused a slice of bacon, but our values bind us: integrity, accountability, diversity, truth, and a love of lifelong learning. These common values help us ensure we are building a company that we’ll be proud of for years to come -- in our case, one that is focused on doing the right thing for consumers. Make sure you’re value-aligned and that as you grow you continue to make decisions that are in line with your values. It’s up to you to live and instill values-based behavior in your employees.

7) There is no turning off when you start a company with your sibling -- and that means everyone is involved. Be sure you’re prepared for that, or set boundaries early-on -- and discuss with the rest of your family, too. In our case, whenever we’re together -- be it holidays, weekends, vacations -- we’re working in some capacity and it’s tough to turn off. Thanksgivings turn into executive offsites, but with turkey, tofurkey and stuffing.

8) Along those lines, have “The Talk” with your families ASAP. Jake and I are lucky in that our wives, parents and other siblings can deal with awkward situations -- we’ve been known to turn Passovers into heated debates about machine learning and product roadmaps. Decide how much you are both comfortable with discussing on home turf, agree with your family, and stick to it (you may need an intervention or two!). Also make sure you celebrate successes with them. Jake was recently honored with a 40 Under 40 win, and our parents were so proud to be there to cheer him on.

9) Family dynamics will always be family dynamics. As the older brother, bossing Jake around came very naturally for me -- I had years of practice. When we had our first major disagreement, we hashed it out with a shouting match at the office -- which, for us as siblings, was typical. But our whole team was terrified that we were never going to speak to each other again. In other words: the office is not your living room. You must work hard to be a respectful and respected leader, and leave sibling-driven emotions at home. This is where a good coach can work wonders -- don’t let your ego get in the way of professional development.

10) Even someone you know as well as your own brother can still surprise and teach you in amazing ways. Seeing someone you know so well in a different -- in this case a professional -- light can be eye-opening. Both of us have learned invaluable lessons from each other through our six years working closely together, often when we least expected it. Be open to growing together as you build your company.

Without a doubt, being co-founders will take over your lives. It’s hectic, hard, and stressful at work and at home. Commit to making time to actually just be siblings. Enjoy each other’s company and remember what brought you together. Ever the math major, I think in equations. Thankfully, when I think about starting LendUp with my step-brother, I can confidently say it’s not 1+1=2, but rather like 1+1=2^10. And co-founder duties aside, there are few things I love more than seeing how my kids just absolutely adore Uncle Jake.