Sysadmins are what you bring in once you've grown enough that operational issues detract from development rather than add to it. A sysadmin should absolutely not be your first hire. At most a consult with an engineer in the early days to get you started. This would help if your coders are used to handing off deployment to someone else. Bluntly, if you completely lack ops knowledge, buy an hour block from an ops specialist that can get you over the rough patches.
My concern with a sysadmin first is that you'll want your early development very tight with your production systems. A sysadmin is the last thing you'll need while doing fast iterations on an MVP. In the early days your need for feedback is high and your operational issues are low. After some significant growth your ops needs will be high, and the feedback value of those issues will become lower (more repetitive less new information). This is where you bring in a sysadmin to manage/automate the repetitive and filter some of the ops issues into actionable information for the development team.
My concern with a sysadmin first is that you'll want your early development very tight with your production systems. A sysadmin is the last thing you'll need while doing fast iterations on an MVP. In the early days your need for feedback is high and your operational issues are low. After some significant growth your ops needs will be high, and the feedback value of those issues will become lower (more repetitive less new information). This is where you bring in a sysadmin to manage/automate the repetitive and filter some of the ops issues into actionable information for the development team.
Edit: Ops guy for over a decade btw.