I've had similar experiences trying to sit somewhere between Architecture and Platform Engineering (enabling a culture of autonomous product team delivery within an environment of enforced design constraints). It takes a lot of work to build towards a role where designing something like this could be possible; I've never seen a company hire for this kind of thing explicitly. Plus, if they've already built it, it evolves without the need of a specialist.

You just need to be in the right place at the right time, I guess.