Two architectural approaches for building scalable WebSocket applications. The first diagram illustrates a traditional Socket.IO architecture using load balancers, multiple server instances, and a message broker (like Redis or RabbitMQ) for routing messages across servers and maintaining global state through a shared database. The second diagram demonstrates an alternative approach using a stateful router that groups users by room and localizes data processing. This architecture reduces cross-server communication by keeping room-specific data local to individual WebSocket servers, potentially improving performance for applications like multiplayer games or real-time collaboration tools.