Unity is what they are using, I just know from seeing it in the browser code and researched it a little last year. https://unity.com/solutions/build-backend. Source: over 1 year ago

I never said that Unreal is bad for non BRs, just that it is very good for BRs. The amount of work they put into making Fortnite work as well as it does puts it way above anything else for large match based shooters. I agree that Unity's old multiplayer code was an absolute mess, and I would have previously suggested using a third party solution. I was saying that I've heard good things about their new multiplayer... Source: about 2 years ago

Anything you put elsewhere is not more secure, unless you are more secure than Apple's servers, which seems highly unlikely. If you don't have it, it can't get compromised. The user has an iCloud account, you can write to iCloud storage without making them "sign in" to your app. It's their data, they can find it in the folder for your app in their iCloud drive on a Mac. And see... - Source: Hacker News / about 1 month ago

Why do you need them to have an account? What on your roadmap requires it? And perhaps you could leverage Game Center accounts for "play" data, which leverages Apple's sensitivity to provide privacy while allowing achievements, multiplayer, and turn-based games, between partners. https://developer.apple.com/game-center/. - Source: Hacker News / about 1 month ago

u/JTostitos is right though that Game Center was designed for this although it has gone out of style with many game studios lately. But it all depends on how the game is designed... If you require constant client-server communications then implementing Game Center doesn't really make sense when you can easily roll your own leaderboard on the server. Source: about 2 years ago