I’m surprised you don’t mention Perl in this list. It’s the de facto Unix scripting language and frankly more suitable to the task than others.

Perl on the command line is beautifully concise; it’s easily embedded into CI/CD pipelines because the q, qq, etc escaped quotes; it has best-in-class regex support; calling external utilities equally concise with qx or back-ticks; etc etc.

Personally I tend to favor C/C++ for the main event and Perl for everything else on the systems side.

JavaScript is obviously ubiquitous on the front-end but it feels very clumsy. Not a huge fan of that on the back-end system it’s just too weird to do simple stuff like “parse a file” or “rip through a directory tree” or call a shell command.