This is my 2019 top language picks. I did not exactly pick them. They picked me.
The Bourne shell was cutting edge in 1977, and it still is today. I have aesthetics issues with it, but it has found a new happy home in cloud computing.
Python and Scala will take you far in backend and data engineering.
The gradual types in Python 3.6 and 3.7 are really a great help but they are very simple compared to TypeScript that probably has the most sophisticated type system these days.
Rust is beginning to make it into cloud infrastructure
Rust also seems like a natural choice for working with WebAssembly.
Terraform feels like a strange combination of Haskell and TypeSafe config. But it also fills a niche in cloud computing for: Infrastructure as code.