You don’t have to be on the Apple ecosystem to use Swift. They have full Linux compatibility and an official (as is supported by the Swiftlang group, not even Apple, thought it’s more or less the same) VSCode extension.

They have a lot of server-side projects going on. They are also increasingly using Swift on the server themselves (not on macOS).

Finally, small nitpick, but it shows you don’t care, it’s written Xcode.