How does Scala support multi-layer fault tolerance in production systems?

Fault tolerance is achieved via retries, circuit breakers, isolation, and supervision hierarchies.

Scala systems implement multi-layer fault tolerance at application, service, and infrastructure levels. At the application layer, effect systems handle retries and timeouts. At the service layer, circuit breakers prevent cascading failures. At the infrastructure layer, Kubernetes restarts unhealthy pods. Akka supervision trees restart failed actors based on failure policies.