I use a Java (Spring Boot) web-service and encrypted calls from the game … you can read more about it here: Gobbo Games — Riders of Asgard - Back-end
The is a reason for choosing this design, it is highly scalable and merely requires me enabling more services behind the HAProxy load balancer in order to support more transactions per second. This is also an enterprise ready design and because I am using Docker, I can immediately spawn up new instances if the load increases or move everything to Azure or AWS if need be.
I write these types of systems for a living and some of my systems are handling 2000 transactions per minute … I use an entity framework to make the marshalling and un-marshalling from Java POJOs to JSON and back again extremely easy.