I'm working on an iOS app that makes extensive use of databases, where users will be able to sync their data to a server. However, I'm terrified of the event that if too many users start using the app, the servers will no longer be able to handle it. I'm not a server guy at all and am not too familiar with how that works, but my question is, why do servers get overloaded and how can that be prevented? Does it have to do with who my server host is? Or is it about the efficiency of my code? If my host is a reliable server, such as Amazon AWS, am I still at risk for server problems? Bottom line is, does it have to do with the way I implement my code, or does it have to do with who my host is?