Resilience and Blast Radius Design

When to Use

Apply this skill when:

• Designing a new system and want to build resilience in from the start
• Reviewing an existing architecture for single points of failure, over-broad blast radius, or missing degradation controls
• Deciding whether a component should fail open (availability) or fail closed (security)
• Planning compartmentalization to limit the impact of a security breach or operational outage
• Preparing an incident response strategy that requires quarantining a subsystem without taking everything offline
• Evaluating whether alternative/backup components are likely to work when actually needed

The core pattern: resilience is not a single mechanism — it is five cooperating layers: (1) defense in depth across attack stages, (2) controlled degradation under load, (3) blast radius compartmentalization, (4) failure domains with component-tier redundancy, and (5) continuous validation that the other four still work.

Before starting, confirm you have:

• A description of the system's architecture or the component under review
• An understanding of which features are critical to users (needed for degradation planning)
• A sense of the organization's risk tolerance and operational capacity (needed for tier selection)