Using Scala for Game Server Development

Studio Kingdom adopted Scala while building the game server for Cookie Run: Kingdom. This decision was made to increase the accuracy of complex game logic, respond to rapid feature updates, and efficiently handle concurrency and scalability issues for a large user base.

Scala's powerful static typing system effectively prevents runtime errors. By resolving null issues through Option[A], restricting the range of values with the refined library, or giving types unique meaning through newtype, bugs caused by mixing up data are blocked at the source.

Furthermore, types can clearly document how a function behaves. Using types such as Option, Either, and ZIO makes it possible to immediately grasp a function's return value, possible errors, and whether it has a side effect just from the code, enabling stable development.

Going further, by leveraging Scala's conciseness to design a Domain-Specific Language (DSL) directly, valid operations that are only permitted for specific tasks—such as transactions between entities—can be enforced at the code level.