C# and SQL Server are what I'm best at. I enjoy front-end work, but lately I get roped in only on back end systems - making new things that scale well and getting existing things to perform better.
I'm trying to be less dependent on the Microsoft stack - For no other reason except for a new experience.
I'm busy following a book on how to create a programming language and interpreter using Golang.
I'm also quite interested in learning a functional language like Elixir.