What position/job is responsible for configuring load balancers, front end reverse proxies, and other network logic for web apps?

I'm interested in a position that will let me configure the network logic for web servers. This could mean spinning up reverse proxies or load balancers for web servers.

I'm ethically not a huge fan of AWS/Azure/GCP, so I'd ideally like to find a position that explicitly deals with network logic configuration using tools like nginx and any non AWS, GCP, Azure hosting platform (even on prem will do). That's just a wishlist item, I'm SCS certified, so I can swallow my morals if I need to. I know it might seem odd to look for something not involving the big 3 for cloud hosting, but that's what I'm interested in.

What particular job/position does this sound like? What companies do this kind of work (preferably free of AWS/Azure/GCP)?