System Design

What it does

Provides a step-by-step system-design playbook: clarify requirements, estimate capacity, define APIs and data models, produce high-level and low-level designs, and identify bottlenecks and reliability patterns. Includes capacity estimation templates, latency and storage references, architecture decision record conventions, and patterns for scaling, caching, and fault tolerance.

When to use it

Use this skill when designing a new service or feature, writing a tech spec or ADR, selecting storage or communication patterns, planning capacity for anticipated load, or reviewing designs for scalability, reliability, or security gaps. It is also useful during architectural reviews and pre-production readiness checks.

What's included

• Scripts: none
• References: capacity templates, ADR templates, diagrams and checklists embedded in the skill body
• Instructions: six-step design process (requirements → scale → API → data model → components → bottlenecks), back-of-envelope capacity calculations, caching and scalability guidance, reliability patterns (circuit breaker, retries, bulkheads), and red-flag checklist.

Compatible agents

Best used by agents integrated with developer tools and code review contexts (Claude-style and similar large-model agents that produce design docs and ADRs).