R, Typescript (and some plain javascript), a little bit of Scala, and Python depending on the sprint and focus , and other less-programming languages but that still require to keep the syntax in mind: Bash, hcl (Hashicorp config language, mainly for Terraform configs)
More painful than the syntax (which really comes back very quickly as soon as you switch), the painful thing is the variety of IDE and related keyboard shortcuts.... how many times I pressed the wrong key combination.... I try to edit my configs to have the most in common, but still...