How does Rails handle large-scale system degradation and graceful fallback strategies?

Rails systems degrade gracefully using fallback responses, cached data, and partial functionality modes.

When dependencies fail (databases, external APIs, or caches), Rails systems must continue operating in a degraded mode. This is achieved using fallback services, cached stale responses, circuit breakers, and feature flags to disable non-critical functionality. The goal is to preserve core functionality even when parts of the system are unavailable.