Hello,i am developing a 2D game with a friend,and we need to make the multiplayer.the game is only multiplayer.we are looking for the same multiplayer than for example the Slither.io.just put nickname and go to play online with more people.what do you think slither.io uses for its multiplayer?thanks for the attention! 
P.D: i use C# for programming
My guess is slither.io uses node.js with JavaScript (perhaps TypeScript or some variant,) and uses WebSockets. There's a built-in module in node.js for WebSockets.
Btw, slither.io has occasional significant lag spikes, presumably because of the JS garbage collector, and/or because of the TCP data-blocking behavior when some packet is lost. If your game has action elements, this may or may not be good enough for you. Then again, if you need to run in a browser, then WebSockets is pretty much the only viable choice.
thanks for the reply.we are making the game in unity for android and iOS.Now we are using UNET and taking our PC as the server.but in future we want to pay servers.Do you think is better to pay servers?or if i pay unity plus i will get servers?i dont know about that.Thank you very much for the attention
P.D. our game doesnt have much action elements,only the contact between the players is important.
