Manager classes in ue4

hi guys

i’m just working on a normal Tower Defense game for test and now i have a little problem with managing the game

in other engines like Unity we use a normal game object which contain a manager component like Wave Manager and placing this game object in our scene but i never saw that kind of managers in UE4

as far as i know i have to use GameMode and GameState classes for managing but im trying to keep things organized and i dont want to write hundreds lines of code in my GameMode class

any suggestion ??

Create manager classes for anything that requires it and initialize/store them from GameMode.

What about putting it into a game instance or module? Its to my understanding that GameMode is for server side code.