Be careful about being "typecast". You may find yourself doing work that is necessary but not something you'd want to focus on career-wise. However, everyone else may start thinking of you as the specialist for that work.

Example from my career - I joined a startup as a senior-level architect. There were only a few tech folks at the time and my background was databases, so I ended up doing a lot of the database work. It was something I was good at, but I considered it part of a past from which I was moving on.

Eventually I was typecast as an operational DBA - a tactical role rather than the strategic one I envisioned. When management decided to adjust my salary accordingly, I had to leave.

Lesson: Communicate to management all the technical roles that are required in your startup. Let them know which ones align with your own career path. Remind them that they eventually need to get others to fill the other roles. You will have to repeat this often, just not often enough to be a pain about it.