Design vs Testing · both proven

frontend-design vs test-driven-development

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.

frontend-design

Guidance for distinctive, intentional visual design when building new UI or reshaping an existing one. Helps with aesthetic direction, typography, and making choices that don't read as templated defaults.

Category: Design
Source: anthropics/skills · 182,147 stars
License: Not stated
Proof model: claude-opus-5-5
Brief: “Build the marketing landing page for Halcyon, a calm AI calendar app for busy founders. Include a hero with a product mockup of the app, a short row of customer logos, three feature sections that each show the product, a customer quote, a pricing teaser, and a footer. Draw any illustrations or product shots with inline SVG and CSS.”
Skill commit: dbd4588

test-driven-development

Use when implementing any feature or bugfix, before writing implementation code

Category: Testing
Source: obra/superpowers · 301,947 stars
License: MIT
Proof model: claude-opus-5-5
Brief: “Implement a function that parses a cron expression (the standard five fields) and returns the next run time after a given date, in TypeScript. Present the work as a single HTML page with two columns: the test file on the left and the implementation on the right, each in a code block, with a short note at the top on the order you did things in and anything you decided not to support.”
Skill commit: bb92a77

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 frontend-design or alternatives to test-driven-development.