When systems fail, degrade gracefully instead of completely:
Examples:
- Netflix: If recommendations fail, show popular content
- E-commerce: If reviews fail, still show product and price
- Search: If personalization fails, show generic results
Implementation:
- Define critical vs non-critical features
- Implement fallbacks for non-critical paths
- Cache previous responses as backup
- Feature flags to disable problematic features
User experience: Users prefer a degraded experience over a complete outage. They may not even notice missing features.