Ask HN: How to become a software engineer as a self-taught front end developer?

I am a self-taught frontend developer with a couple years of experience. Though software engineering is a broad term that may cover some aspects of what I do professionally, I do not consider myself a software engineer. Maybe it's the lack of formal CS education or having minimal experience developing actual products as opposed to UIs for them.

Is being a software engineer a state of mind or an actual profession that comes with certain prerequisites?