jobs involving servers and networking on a low level?

I started learning django and creating some projects the biggest of which was a chat application which got me learning about rest apis and websockets and async programming and other stuff.

I soon realized that servers and networks were my passion and was pretty confident about it until I realized that my real job won't be as fun as my projects.

The most fun part of my chat application was writing the websocket consumers(not that it was good but it was better than the rest), not the restapi or designing the database models and other things. But afaik in a real job as a backend dev you don't often write consumers from scratch and other technical stuff and your focus is mainly on the app's services and expanding them, adding email verification or migrating databases and other things.

Are there any jobs which require someone to write low level code for communication between computers? or just any jobs that doesn't get me involved on higher level things, I just want to work on the underlying foundations, creating the thing which makes websockets possible for example.