Use when designing system architecture, integrations, tech specs, technology choices, or evolving an existing system where FR/NFR, constraints, scale, reliability, or current product capabilities materially affect the design. Triggers include design, architecture, how to build, integration, spec/ТЗ, спроектируй, архитектура, интеграция, как построить. NOT for routine implementation, debugging, or code edits when no architectural decision is at stake. This is the PRIMARY entry point for design requests; a knowledge-grounded design skill is used as an independent grounding track when available (discovered by role), never the entry point.