Infrastructure engineering as a foundation, since all this stuff ultimately needs some hardware, that has to be provisioned. Not to speak of plumbing/wiring stuff together and things like security/compliance…

DevOps/Automation to get people (no matter if current devs or soon prompters) actually deliver things and/or speed up delivery/feedback loops.

I picked up both after having mastered frontend/backend stuff and getting bored… hope it holds in the coming future!