That's like saying you start a company by yourself and you can't call yourself a CEO. CTO, at any size, still has a lot of concerns that aren't just code level,

That's like saying you start a company by yourself and you can't call yourself a CEO. CTO, at any size, still has a lot of concerns that aren't just code level, so the title is valid. However, context is very important. Anyone that looks at someone's resume and sees that they're the CEO of a single person company will understand that they're on a different level than the CEO of a publicly traded company. EDIT: the other thing that gets conflated here in these title discussions is non-technical founders thinking they need a CTO, when really they just need a lead developer. That definitely muddies up the conversations.