#2
13th Dec 2017 at 8:35 PM
I'm pretty sure you can hire a DJ through the "Services" option in your Sim's smartphone, similarily how you can hire maids/pizza/etc as long as you have a DJ booth in the lot.
I haven't actually done it for a while since my latest household has both a mixologist and a DJ, but I distinctively remember throwing a party at a Sim's apartment once and hiring a DJ and a bartender.
EDIT: Okay, confirmed. You can hire a DJ for any lot that has a DJ booth in it, even if your Sim doesn't own that lot, similarily how you can hire magicians, sing-a-grams, etc. It's under the services tab in your phone.