Game Programmer for Private Server Project

I have an open source game code written in C# and Java that I'd like to use to create a private game world on a server. This project requires someone with experience in game development and server-side programming.

Key requirements:
- Utilize an existing open sourced game code written in C# and Java
- Create a private game world on a server
- Ensure it's playable on both PC and mobile platforms
- Implement multiplayer capabilities

Ideal skills:
- Proficient in C# and Java
- Experienced in game development
- Knowledgeable in server-side programming
- Familiar with creating multiplayer games
- Prior experience in adapting existing code

Your role would be to take this existing code and set up a private game server that can be accessed and played from both PC and mobile devices. The server should support multiplayer functionality for a seamless gaming experience.