Refactoring Massive App Delegate using Mediator pattern. See blog post for more details: https://www.vadimbulavin.com/refactoring-massive-app-delegate

RefactoringAppDelegate-Mediator.swift

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?

    let mediator = AppLifecycleMediator.makeDefaultMediator()

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        return true
    }
}