Use when the user needs to make system-level structural decisions: service decomposition, module boundaries, technology selection, data storage choices, API contract design, or deployment topology. Can be used AFTER brainstorming to formalize decisions, or ALONGSIDE domain skills (rm-hero-architect, ros2-development) which provide domain knowledge while this skill provides structural framework. NOT for open-ended idea exploration alone (use brainstorming) or domain algorithm design alone (use domain skills). Triggers on 'design the architecture', 'how should we structure this', 'what tech stack', 'service boundaries', or ADR documentation needs.
2026-04-09