Use this skill when engineering judgment above the code level is needed - "menurutmu arsitekturnya gimana", "trade-off nya apa", "kapan refactor", "monolith vs microservice", "build vs buy", technical debt decisions, scaling decisions, mentoring-level explanations of engineering principles, or reviewing a technical direction. The principal-engineer brain - principles, trade-offs, and how to decide. Do NOT use for executing the code itself or for process/lifecycle questions (sdlc-master).
