system-design

This skill should be used when the user asks to "design a system", "design <a product>" (e.g. "design WhatsApp", "design a URL shortener", "design a news feed"), "high-level architecture for…", "how would you architect…", "system design interview", or wants to scope, diagram, and justify a backend/distributed-system design. It runs a reasoning loop — clarify, estimate, design, weigh trade-offs, stress-test, iterate — and routes to focused building-block skills. Use it whenever a request is an open-ended design problem, even if the user doesn't say "system design".