Graceful Degradation and Fallbacks

Containing a failure protects the system, but fallbacks decide what the user sees when a dependency is down.

Graceful degradation means preserving as much value as possible instead of failing completely. A product page can load without recommendations. A personalized feed can fall back to popular posts.

This chapter covers static defaults, cached responses, dropping optional features, queuing writes for later, alerting when fallbacks activate, and a checklist for designing safe fallbacks.