Testing vs Design · both proven

systematic-debugging vs tailwind-design-system

Both skills were run through Claude twice: once on a fixed brief without the skill, once with it. The briefs differ because each is written for the job the skill claims to do, so compare each skill against its own baseline, then decide which difference matters for your work. They are in different categories, so this is a choice of job, not a head-to-head on the same job.

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes

Category: Testing
Source: obra/superpowers · 301,947 stars
License: MIT
Proof model: claude-opus-5-5
Brief: “A Node.js API returns 500 for about 1 in 200 requests to POST /orders. Logs show 'TypeError: Cannot read properties of undefined (reading "id")' at orders.js:48, which reads req.user.id. The route is behind an auth middleware. The failures started after a deploy that added a 30-second cache on the session lookup. Present your diagnosis and fix as a single HTML page: what you checked, in order, the root cause, the code change, and how you would confirm it is fixed.”
Skill commit: bb92a77

tailwind-design-system

Build scalable design systems with Tailwind CSS v4, design tokens, component libraries, and responsive patterns. Use when creating component libraries, implementing design systems, or standardizing UI patterns.

Category: Design
Source: wshobson/agents · 41,103 stars
License: MIT
Proof model: claude-sonnet-5-5
Brief: “Build a product card grid for an online plant shop with filters, price, and add-to-cart buttons.”
Skill commit: 0874a27

We don’t pick a winner for you: the pages are the evidence. Both proofs can be repeated with the brief, model and commit shown above. See alternatives to systematic-debugging or alternatives to tailwind-design-system.