What is a Platform Engineer?
I think you would be hard pressed to get a straight definite definition of a Platform Engineer.

Where I'm currently positioned everyone on the team starts out with their own special role but very quickly the end-game seems to be to feel comfortable enough to be called, or to call ones self, a platform engineer.

When I was first told that officially a platform engineer the brief explanation of what that meant, for me at least, was that I was going to need to do a whole lot more defending of my platform.

I wasn't quite so focused on helping our developers directly (although that's still the goal obviously) but as the platform owners our jobs was mostly to make sure that our developers where being good citizens by making sure we designed the platform so that we could show them what they did wrong if something happened and we could give them all the information they needed to fix their code.

The obvious implication of this is that our platform is perfect, which it obviously isn't. But at least we can support the developers in a way that gets them working on a solution on their end while we're fixing up our side of the agreement.