Cross-Cutting Concerns

The non-functional requirements that cut across every topic and are the architect's daily vocabulary. They don't belong to any one system - they're lenses you apply to all of them.

Planned:

• Reliability - SLOs, error budgets, redundancy, graceful degradation, chaos
• Observability - logs, metrics, traces; the "three pillars" and what each is for
• Security - authn/authz, secrets, defense in depth, threat modeling
• Performance - latency budgets, tail latency, caching strategy, profiling
• Cost - the fourth axis; cost/request, build-vs-buy economics
• AI-native NFRs - eval & regression, hallucination/grounding, token cost, prompt-injection, non-determinism