The CTO role is completely different depending on size of company. Here is my experience.
Startups: <10
I have had roles in small start-ups as CTO, but did the role of a Lead Developer in reality, it was important to get investment that they had a CTO on board that had a track record and could talk to investors, but I still had to build everything as well. Thinking back it would have been better to get a 2 day a week CTO and a full time Lead dev.
Mid Size:10>40
In a company this size with a dev team of 10ish its more of a Development Manager Role, this is some times worst than a startup as you have to be hands on, speak to investors and run a team.
Larger:>50
This is where a real CTO can really make a different, by this size you would have a couple of functional managers as your direct reports to look after day to day and get the time to focus on culture, team, investors, new tech, presentations etc.
Startups: <10 I have had roles in small start-ups as CTO, but did the role of a Lead Developer in reality, it was important to get investment that they had a CTO on board that had a track record and could talk to investors, but I still had to build everything as well. Thinking back it would have been better to get a 2 day a week CTO and a full time Lead dev.
Mid Size:10>40 In a company this size with a dev team of 10ish its more of a Development Manager Role, this is some times worst than a startup as you have to be hands on, speak to investors and run a team.
Larger:>50 This is where a real CTO can really make a different, by this size you would have a couple of functional managers as your direct reports to look after day to day and get the time to focus on culture, team, investors, new tech, presentations etc.