Ask HN: How did you get started as a (Fractional) CTO?

I've been a Full Stack web developer for almost 10 years, and a Freelancer for 2. I now want to move in a more strategic direction, so I'm looking at moving into a (Fractional) CTO role.

If you've been previously been a CTO, how'd you get into the role? I'm interested in hearing about other people's experiences, especially in smaller companies / startups.