I got this problem in bloomberg system design:

• So there is already a game service which enables people play like a game poker, now a lot of users based on their ranking/elo scores etc. enter into a game or are suggested a type of game comparable to the same level.

• After users enter into a poker room and a game has started, its some other service's responsisbility to take over, we don't need to design that.

• The last thing they asked was how would you scale if there are users from all over the world, they could enter into the game and it is faster, like a player from russia, one from india, one from Europe

Someone can explain how would they do that, keeping in mind, a user can withdraw from a room, after users have entered a room , we have to decide when to start a game, suggest users some rooms that are live to enter and scale all this on a globa level.