Joseph Baena inherited his father, Arnold Schwarzenegger's muscular genes and has a great aesthetically looking physique. What does he do on a back day?
He does two variations of the lat pulldown
The wide grip lat pulldown targets your delts and upper back muscles like in a pull-up, and the close grip targets your middle and upper-back muscles.
Hyperextensions
Hyperextensions target the lower back and is a great exercise for strength building.