Ask HN: Opportunities in Embedded, without IoT hype?

For context, I have been learning embedded-related concepts here and there, assembly language, operating systems etc..

I am interested in the premises eg efficiency, and frugality. However the field seems to be full of two kinds of jobs / opportunities - either the orthodox embedded companies that are not very good with technology choices and, or new age IoT all internet cloud connected dustbins bullshit.

I would like to know whether there are any promising sub fields or topics which I can have a look at, where I would be able to work on software optimization and interesting challenges.

Thanks