Other people said it already that CTO may mean different things depending on context.
From my exp CTO in small startup is marketing tool and it does not mean real "the CTO". In small org CTO is simply "do it all in no time" type of job, that includes hands on coding, infrastructure, but also hiring, overseeing and managing people. You also need to understand code lifetime and methodology of your choice, how to use it to provide good enough time estimates. And all of this will lead you to be probably replaced once organization grows.
From my exp CTO in small startup is marketing tool and it does not mean real "the CTO". In small org CTO is simply "do it all in no time" type of job, that includes hands on coding, infrastructure, but also hiring, overseeing and managing people. You also need to understand code lifetime and methodology of your choice, how to use it to provide good enough time estimates. And all of this will lead you to be probably replaced once organization grows.