I've been messing around a bit with node/typescript with angular. The VSCode editor has some really nice tooling around it that makes it nice to use. That was semi amusing for a few months. Maybe I will try react or rust next.
Python is always useful too. It is a really nice 'glue' language where you can hack up something semi useful pretty quickly. I have seen and written large projects in it. But I would not really recommend it for that. Sometimes it 'just happens'. Powershell falls in this same camp but the tooling is not as nice but having the power of .net to do stuff is nice though.