In this context, does "manager" refer to a CEO? Or an executive?
Answer from a Native speaker
Not necessarily, no! Later, he says he was part of a group that founded a company, but it sounds like he managed part of the company, not that he was CEO. They could've chosen someone else in the group to be CEO. It's very rare that someone would be a CEO and a manger since these are quite different titles. One could be both if the business was small or run a certain way. Ex: The CEO is having a meeting with all the managers. Ex: I run my own business by myself. So, technically, I'm a CEO, manager, and worker.