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

MassiveAppDelegate-Commands.swift

protocol Command {
    func execute()
}

struct InitializeThirdPartiesCommand: Command {
    func execute() {
        // Third parties are initialized here
    }
}

struct InitialViewControllerCommand: Command {
    let keyWindow: UIWindow

    func execute() {
        // Pick root view controller here
        keyWindow.rootViewController = UIViewController()
    }
}

struct InitializeAppearanceCommand: Command {
    func execute() {
        // Setup UIAppearance
    }
}

struct RegisterToRemoteNotificationsCommand: Command {
    func execute() {
        // Register for remote notifications here
    }
}