The answer to the question seems very surprising to people with no experience from a real tech startup. By real, I mean starting the company from scratch. No people, no funding, no nothing but an idea. So I'd thought I should give my 10 cents on the subject.
First off, all companies need a CEO. Most commonly this is not the same person wearing the CTO hat and it really shouldn't be either as the roles are so different as I will explain.
So, from the get-go, you are two people. A CEO and a CTO. Perhaps you don't even know each other very well when starting up, but you will. Hopefully, you get to know one another on a very deep level. Your strengths and weaknesses must be exposed in order to push the company forward.
A CEO does almost everything that the CTO can't(and shouldn't) do. HR, legal, financing, marketing, and investor relations are just scratching the surface of what a CEO needs to do in a tech startup. As my CEO Niklas use to say: "I'm in the Jean-Claude Van Damme split". There is truth in that, the CEO really needs to multitask.
The CTO on the other hand needs to be the focused one. Quality and speed are the keywords. In everything you do. Make sure to deliver quality and on time. Maintain the scope of the product and say NO loud and clear when scope or quality is threatened. Everybody from the CEO to early adopters will want your ear. Be the voice of reason and don't forget the roadmap you have. Continuously think about what the next steps are and believe in yourself. Saying no is probably more important than saying yes.
As the CEO and CTO roles are so different it will take time before you can work together without friction. For me and Niklas, it took nearly 3 years to really get in sync, understand the other and find the best way to help each other. First, you need to get comfortable in your role, then you need to know the other person's role and pains, only then can you identify how you can help the other. Some never do and I think it is one of the top reasons a startup fails.
You are going to war(the only way I can explain it) together, you have to go through hard times to build real trust. Will the other person stay when the bullets start flying? Will he crack under pressure? Another thing that never goes into people's calculations is the respective families. Yes! trust me, your partner will also need to step up, that's what it takes. So besides creating your new startup family there will be a similar journey for your first family. There will be friction there too 😂
So, to succeed as a tech startup CTO the only thing you need to remember is to get in sync with the CEO asap, get to a point where you really are helping each other and build trust. Stay focused, never compromise quality, deliver fast and handle all the pressure and friction during.
Oh... almost forgot, you probably will need to do this for 14 hours a day, 7 days a week for years until you get to a point where you can take a break. Sound like something you would like to do? (the word try can't be used in a startup, it's like death)
It's a ride and it's hard, but it is also very rewarding and fun. I highly recommend the journey. Now, show me your war face!