CTO's deputy for software architecture using Clean/Hexagonal Architecture principles. Socratic approach - asks probing questions to help YOU make informed design decisions. Guides through Discovery → Modeling → Boundaries → Scaffolding phases. Outputs TypeScript scaffolds with ports, adapters, and domain layers. USE WHEN user says 'architect', 'system design', 'hexagonal', 'clean architecture', 'ports and adapters', 'design this system', 'structure this project', or needs help thinking through c
SkillScore58Maintained
Automatic
◆Coding pack
Last verified 8/27/2026
What it changes
Passed 13 of 23 test cases with the skill, and 6 of 23 without it.
Without skill25%
With skill58%
Checks it passed that the model alone missed
Uses Mermaid diagram syntax for all visual models.
Separates process diagrams into a processes subfolder.
Refuses to format flowcharts using ASCII text characters.
and 8 more in the full report
9 fixed5 passed either way9 still failing1 broke
Pass-rate lift
+33 pp
Tokens
+29%
Agent turns
0%
Response time
-63%
Model gemini-3.6-flashMeasured 8/27/2026v214 of 24 cases passed with skill · 23 comparable
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 9 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 9
Prompt
We are starting a new design session for a social network messaging backend. How should progress across the 5 design phases be tracked during our interaction?
What was checked, without and with the skill
Checked
Without skill
With skill
Uses a TodoWrite checklist tracking progress across design phases.
Missed
Passed
case-19 · gemini-3.6-flash · 8/27/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md488 linessingle file
执行环境
路径类型
说明
使用方式
此技能提供模板和指导，无需本地脚本执行
调用场景
当用户需要系统设计、架构文档、技术选型时自动激活
输出位置
docs/design-catalog/ 目录（相对于项目根目录）
路径说明
无本地脚本依赖：此技能生成文档模板，不涉及本地脚本执行
生成的目录：保存在执行命令时的当前目录下的 docs/design-catalog/
项目上下文：基于当前工作目录确定项目根目录
System Design Through EventStorming
Overview
Transform requirements into navigable design catalogs using EventStorming methodology and Mermaid diagrams.
Core principle: Progressive elaboration through event-driven thinking, producing token-efficient visual artifacts in standardized catalog structure.
Announce at start: "I'm using the system-design skill to create a design catalog for your system."
When to Use
Use when:
User wants to design a new system
Requirements exist but design doesn't
Need structured thinking before implementation
Team needs shared visual artifacts
Don't use when:
Adding features to existing system (consider brainstorming instead)