PS: I work in distributed system software development(cloud, kubernetes, etc..) but any thing that enriches your knowledge in general will do too.
https://www.coursera.org/courses?query=business%20communicat...
"Let us change our traditional attitude to the construction of programs. Instead of imagining that our main task is to instruct a computer what to to, let us concentrate rather on explaining to human beings what we want a computer to do."
-Donald Knuth
Creative writing too, great to help with documentation, blogs, and organizing thoughts.
Did a sailing class too, not much related to IT, but interesting. Especially navigation, lat lon, the instruments used, etc.
As for IT related coursea, I think re-taking basic classes like compilers, linguistics 101, data structures, calculus, is always fun to remember and learn as well.