If it has to be about operator sdk then it’s not the best example because it doesn’t use operator sdk, it uses the lower level client-go directly (I’m just commenting this because the original post was asking about operator sdk). I personally prefer client-go, the operator sdk interface never really spoke to me.
(Full disclosure, I’m the co-creator and one of the maintainers of prometheus operator)
(Full disclosure, I’m the co-creator and one of the maintainers of prometheus operator)