In most companies I've been a part off, including multiple >$1B tech companies, the CTO's focus is not on the engineering. That's the job of a VP Engineering or some similar position.
CTO (which will sometimes have a "CTO office") is to work besides the engineering on investigating new technologies and ideas that are beyond what the engineering organization would have otherwise done on the day to day. They are also an authority on all technology in the company but are not in the engineering "chain of command".
That said this is not universal, there are organizations where the CTO does lead the engineering organization. I think that's sub-optimal because there is always going to be tension between the day to day and the broader scope and those should be different roles.
In a startup, it is more common for a CTO to lead engineering because there is not yet enough to justify having both a VP Eng and a CTO and perhaps most of the work is around figuring out technologies. But as the company grows it makes sense to separate those functions.
I've seen both. A CTO office that also leads engineering--typically via a direct report to the CTO--and an organization where the CTO is largely an external evangelist (typically with a small staff) while engineering is a separate organization--though hopefully aligned. The view here where CTO is also the head of day-to-day engineering operations and technical vision is more of a small company/startup thing. The two are often separated to at least some degree at larger operations.
This description is accurate to what I have seen and what I do. I'm a CTO of a >$1B tech company, and my roles is focused around the technology innovation, and that includes evaluating and prototyping new tech. In my particular case that role also includes the operation of our technology because that is very central to our business - and also extremely focused on high reliability.
When I was CTO of my startup I had far more direct engineering development work, but that is typical in the building stage.
As for the core of this post, the one thing I do agree with is the ability of the CTO to actually be technical. I write code all of the time, but not for our products. The goal is to remain both technically proficient but also focus that proficiency on leadership.
In most companies I've been a part off, including multiple >$1B tech companies, the CTO's focus is not on the engineering. That's the job of a VP Engineering or some similar position.
CTO (which will sometimes have a "CTO office") is to work besides the engineering on investigating new technologies and ideas that are beyond what the engineering organization would have otherwise done on the day to day. They are also an authority on all technology in the company but are not in the engineering "chain of command".
That said this is not universal, there are organizations where the CTO does lead the engineering organization. I think that's sub-optimal because there is always going to be tension between the day to day and the broader scope and those should be different roles.
In a startup, it is more common for a CTO to lead engineering because there is not yet enough to justify having both a VP Eng and a CTO and perhaps most of the work is around figuring out technologies. But as the company grows it makes sense to separate those functions.