This is a bit of a narrow view of a very vague term. Working with many different sizes of organisations whomever is labelled CTO is the person accountable for the technology decisionmaking. Sometimes that’s a legacy developer, sometimes that’s the first sys admin. Sometimes it’s the VP of engineering. Sometimes that’s the guy that maintains the best relationships with software vendors. Sometimes it’s the person that was hired internally to explain the tech to the CEO. Sometimes it’s a guy that is just a public figure used to promote and maybe do DevRel for the org. Sometimes it’s the Architect that designed the ecosystem. Sometimes it’s the ancient programmer that has kidnapped the entire codebase so that no-one else can sanely work on it. Sometimes it’s a six sigma type that setup the ticketing system, PRs and the release process.

At any size, the CTO is whatever the org needs him to be.