Once again, support crew members are available, and you can hire them to help you with the preparations and facilitate the heist. Both these and the setup missions are completed in Freemode, and you can also do several optional ones to make it easier. It’s similar to the Doomsday Heist, as you once again have to complete Prep Jobs to reach the Finale. You can complete the heist with only one other player or more. It was added to the game in December 2019 as part of the Diamond Casino Heist update.
Diamond Casino Heist is one of the several heists players can do in GTA Online, the multiplayer part of GTA 5.