Testing vs Design · both proven

differential-review 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.

differential-review

Performs security-focused differential review of code changes. Adapts analysis depth to codebase size, uses git blame for context, calculates blast radius by counting callers, checks test coverage of modified code, and generates a markdown report. Use when reviewing a PR, commit, or diff for security vulnerabilities, checking whether a change re-introduces a previously fixed bug, asking what else…

Category: Testing
Source: trailofbits/skills
License: Other
Proof model: claude-opus-5-5
Brief: “Do a security-focused review of this change and present it as a single HTML page. Commit: "Allow admins to impersonate users for support" +app.get('/admin/impersonate/:id', async (req, res) => { + if (req.cookies.role !== 'admin') return res.sendStatus(403); + const user = await User.findById(req.params.id); + req.session.userId = user.id; + res.redirect(req.query.next || '/'); +});”
Skill commit: 2be6433

Without the skillWith differential-review

⇆

Without, runWith differential-review, run3 independent runs per side, none selected by hand.

Download the with-skill page

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
License: MIT
Proof model: claude-opus-5-5
Brief: “Build the shop page for Verdant, an online plant shop: a header, a filter sidebar with categories, light and price, a responsive product grid with at least nine plants drawn in inline SVG, prices, ratings, add-to-cart buttons with a cart count that updates, and a footer. It should feel like a premium storefront.”
Skill commit: 0874a27

Without the skillWith tailwind-design-system

⇆

Without, runWith tailwind-design-system, run3 independent runs per side, none selected by hand.

Download the with-skill page

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 differential-review or alternatives to tailwind-design-system.