If you work alone on a very complex project, the task can be so huge it discourages you. You will have to spend too much time on it before getting the slightest

If you work alone on a very complex project, the task can be so huge it discourages you. You will have to spend too much time on it before getting the slightest results. Coding is hard, bugs can be depressing, and when you are alone, you struggle alone. It can be daunting. The more complex the project is, the more daunting it is when things don't work. On the other hand, when you have another technical cofounder, first of all you can share the work and accomplish more. Second, having someone to bounce ideas with, and having to coordinate, actually helps you clarify your ideas and thus makes those ideas more robust. When you code alone, sometimes you get into a rabbit hole and you loose sight of what is important, you neglect some key details etc. A technical cofounder acts as an accountability partner, pushing you to always do your best because you know your work affects another person, motivating you when you are down and you motivate them when they are down. Having a non-technical cofounder can be nice too, but it really depends on the idea. If the idea needs more business sense than technical prouesse, then technical + non-technical is good. But if the idea implies a high level of technical prouesse, then you definitely need a technical cofounder, else you just won't make it. For example, nobody will try to train a 70B LLM alone, you need a team (and a lot of GPUs).