Assembly aside, all the things you mention are things I would expect a software engineer to understand. As an engineer in my late twenties myself, these are exactly the things I am focusing on. I'm not saying I have a particularly deep understanding of these subjects, but I can write a recursive descent parser or a scheduler. I value this knowledge quite highly, since its applicable in many places.
I think learning AWS/kubernetes/docker/pytorch/whatever framework is buzzing is easy if you understand Linux/networking/neural networks/whatever the underlying less-prone-to-change system is.
The one at your local university. Either one named something like "Introduction to Networking" or "Introduction to Distributed Systems", depending on what you want to learn.
You could also read some books. Rami Rosens "Linux Kernel Networking - Implementation and Theory" is quite detailed.
The "UNIX and Linux System Administration Handbook" (Nemeth et al.) covers a lot superficially and will point you in the right direction to continue studying. It's very practical-minded.
For low-level socket programming, you can probably read "Advanced Programming in the UNIX environment". It might be more detail than you need though.
At the other extreme, if you want to study distributed systems, you could read Steen & Tanembaums "Distributed Systems"
I think learning AWS/kubernetes/docker/pytorch/whatever framework is buzzing is easy if you understand Linux/networking/neural networks/whatever the underlying less-prone-to-change system is.