Hi, I have done the same as you are planning to do. I was also the CTO (and founder), while my cofounder was for the sales side. However my company was already

Hi, I have done the same as you are planning to do. I was also the CTO (and founder), while my cofounder was for the sales side. However my company was already more advanced I assume and I had already done a partial exit. I left after about 10 years of having founded the company, and don't regret it. Sure, I might not ring the bell later when we IPO, but I don't need this. That's just an ego thing, but that you have to accept :). My cofounder didn't like so much that I was leaving, reasoning that the company would be worth less later, wouldn't grow so fast, or engineers or others employees would leave. I stayed another 1 year working 50% until I left completely (They still though tried to retain me later on, but I declined). At the end no one of the employees left, as they all understood why I was leaving. Just talk to your cofounder and explain him why you are leaving. I assume if you haven't yet exited, and that he would request some parts of your shares to be given to a replacement CTO. I think this is fair. In my case, the replacement CTO was a internal engineer I hired 8 years ago, and I was free to leave already years before. At the end, a new person can also bring in new ideas, sometimes better, sometimes worse. And it's also great if employees see that they can progress in the company. I still very much care though about my former company and still have lots of friends there (not just IT), and I'm still a large shareholder.