I did a few Codewars kata. I don't know which ones to add. All of them are here: https://www.codewars.com/users/Ramanuj-Sarkar/stats
I figured this is the most surefire way to show that I actually can code in C++ and Java (especially Java).
I still can't think of a good way to show I can code in R, though.
I can barely code in Kotlin and Rust.