After more than one year of development, Wooga is heading for the global launch of its game "Kingsbridge"! This is the first game at Wooga with a backend written in JRuby! The talk includes an introduction to the problems that were solved by choosing a stateful applicaton server. I will explain constraints, benefits and obvious differences to traditional database backed application servers. Safely sharing state in a concurrent environment using JRuby Using Java concurrency utils in JRuby Sample problems solved, backed up with code Practical tips for capacity planning