Working as a CTO has been an interesting adjustment. The majority of my career has been working as a developer in the proverbial tech startup trenches. In some ways the job is a simple evolution; in others, a significant leap.
The real job of being a tech startup CTO runs counter to the hype of the industry: the role is more pragmatic than visionary. Yes, it's my job to articulate how technology serves the business, to identify new opportunities, and to help define the nature and culture of the business ... but I still spend a lot of time in the developer trench, writing code and solving engineering problems.
That said, it's very difficult (if not impossible) to have a stable dev team or mature architecture at an early stage startup. Even the fundamental goals of the business are subject to change dramatically. The critical task of a startup CTO is figuring out how to deal with those changes -- quickly understanding and articulating business risks and opportunities, then finding the right development practices, identifying the key technologies, bringing together the right people ... then changing hats and cranking out the code.
Of course, this is not a linear process. The CTO wears a lot of hats, and serves four masters: the customers, the board, the other senior managers, and their employees -- none of whom are easily satisfied. The customers won't have all of the tools and support they want, the board is very concerned with ROI and cash flow, peers on the management team are putting out their own fires, and all of the employees are guaranteed to have too much work. A CTO doesn't have a single boss -- they are beholden to many people.
From that perspective, a startup CTO must handle being pulled in different directions by many important people. The CTO may not have the power to dramatically change the board or their peers, but they can lead employees by example, and advocate for doing what's right for the customers. There are also external partners to negotiate with, herds of outside sales people who want to sell you their services, recuiters who claim to have a lock on the top talent, and myriad lesser opportunists who simply hunt down CTOs just because of the title.
It's a little awkward, but I think a startup CTO should also have a reasonable expectation about how long they will remain the CTO. The demands of an early stage company are vastly different than an established company, and require different kinds of leadership. Some people are able to shift those gears, others aren't. When a company takes on a significant amount of investment, those changes happen sooner than later. When a company gets acquired, the CTO probably won't retain their title or responsibilities.
This all adds up to a job that is terrifying but thrilling, and for the right kind of person, thoroughly satisfying.
It's a weird job, but I love it.