Ask HN: What are the expectations of a CTO at a small startup?

I’m currently a co-founder and CTO at a small startup of only 3 people. The 3 titles we have are CTO, CEO, and CPO. One of the things that has recently come up are what kind of expectations are warranted for a person with the CTO title? I have a general idea in a larger corporation but what would you expect of a CTO at a very early stage (3 people) vs 10 people?