what are the skills required to be able to create a program like virtual dj?

what are the skills required to be able to create a program like virtual dj?

what are the skills required to be able to create a program like virtual
dj, you may be able to realize in python?
What I ask is just "what course of study should follow a person to be able
to make it happen and what languages?" and there may even be able to a
person?