What back-end technology should I be looking at for online games?

I want to create a simple online game. I have a decent amount of programming experience, so I can learn the barebones pretty quickly. What back-end technology should I be looking at for online games?
Should I be looking at IaaS?
If I'm understanding AWS correctly, it's pretty agnostic to the language I'll need to run my gaming server.
I understand it's good for scalability as well.
one thing I'm concerned about is running multiple instances of the game in different locations. I think IaaS will help out with that as well. It should make it easier.
Running multiple instances sounds like something that could be accomplished by just renting multiple servers in different locations, but having those servers communicate between each other may be more difficult than using an infrastructure all managed by a service like AWS.

: )
Thanks for any insight

------------edit
after a little more research, it seems like unity has quite a bit built in to manage multiplayer games.

The next thing I'll be exploring is getting a similar game experience in the browser, desktop app, and phone app.

I guess I'll just grind through all of the tutorials associated with unity so I can level up to that point.

 

It entirely depends on how you want to design your game's network architecture, which itself depends on how you want your game to work.

A single game world MMO, where players shift from zone server to zone server as they cross a large map, would have entirely different requirements from a player hosted match based FPS, entirely different again from a direct connection based multiplayer RTS, and yet again from a player hosted dedicated server RPG.

I'd recommend first considering how you would want to implement your own game idea, research several networking solutions, and try to find the right fit for your game's requirements.

I'd avoid Unity's Unet solution by the way, as it was recently deprecated and will be removed in a few months. So I wouldn't start a new project with it.