I used to be an Erlang engineer, and you would have needed very explicit security controls around being able to attach to an Erlang cluster to get the "insider

I used to be an Erlang engineer, and you would have needed very explicit security controls around being able to attach to an Erlang cluster to get the "insider your program" experience. This was in FinTech, so I'm familiar with the constraint. I would imagine you'd need the same thing for accessing the runtime of any production deployed application(s) in such an unfettered manner. Erlang, Lisp, C, or other?