Family office accounting systems

Looking for some advice. I recently accepted an offer to work for a family office, they basically have one bank account with cash in at the moment but I am going to build out the finance infrastructure.

Apparently they have a couple of operating businesses but are aiming to move towards a US endowment style portfolio.

I was wondering if anyone has experience with implementing accounting systems for family offices and knows what systems people tend to use?

My experience is out of date unfortunately.