Is it possible to make money using your Linux knowledge if you're not a developer? I know I can become a professional devops or sysadmin if I take some courses and master advanced networking. But is there something I can do now as an average, moderately experienced linux user?
I did nearly a decade. DE's (or just wms) on devs' desktops and obviously ssh or console shells on server and network hw. Devs may or may not take care of their own software, though.
Also network protocols, sniffers, support, hardware, security... It tends to expand and admins are the goto for tech questions. So it's kind of a know everything about everything job. And a very thankless one, since if you do your work right, nobody will even notice what's going on since everything just works.