How can the architecture of a stateful system be divided to ensure its scalability and resilience?

For scalability and resilience of a system that maintains state, the architecture can be divided as follows:

• Layer separation: separate data processing logic from state storage.
• Sharding: split the state into parts (shards) to distribute load across multiple nodes.
• Data replication: for fault tolerance, store copies of the state on multiple servers.
• Message brokers: for asynchronous event exchange between components.
• State management service: for example, use a dedicated service with an API for accessing and modifying the state.

This approach allows horizontal scaling of the system and ensures resilience to individual component failures.