Android Servers

You can do it in php. Facebook also uses php. There are many computer languages that can develop servers. In Korea, the current java + spring framework is the mainstream when developing it as an SI project. You can use node.js to develop javascript from the back end to the front end, or you can use python or ruby. I know that you use Python or ruby a lot in startup. But language learning isn't the only thing you need to build a server.

You have to think about many things, but if you think about it because it's limited to language/implementation

You must first determine the protocol.

Are you going to use the http that many people use? The advantage is the ease of deployment, but it is slow.

You said sns, but it can be disadvantageous for handling large amounts of traffic.

In terms of performance, it would be most advantageous to receive packets in raw tcp. There are several asynchronous socket frameworks. There are easy-to-use alternatives, such as Python Twisted, Java Netty, and boost dot net on c++ and super socket.

Even http has an advantage in throughput with nginx for asynchronous communication.

Nowadays, size and easy-to-handle json are much more used than xml.

In other words, if http, when you call url on Android, you will receive json from httpd (web server).
And so, we're going to use the json that we received from Android, and we're going to use it as an unmarshaling.