Proven skills / Compare

Design vs Frontend · both proven

improve-codebase-architecture vs vercel-react-best-practices

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.

improve-codebase-architecture

Scan a codebase for deepening opportunities, present them as a visual HTML report, then grill through whichever one you pick.

Category
Design
Source
mattpocock/skills
License
MIT
Proof model
claude-opus-5-5
Brief
“Here is the orders module of a small Express app. ```js // orders.js const db = require("./db"); const stripe = require("stripe")(process.env.STRIPE_KEY); const mailer = require("./mailer"); async function createOrder(req, res) { const { items, couponCode } = req.body; if (!req.user) return res.status(401).end(); let total = 0; for (const i of items) { const p = await db.query("select price, stock from products where id = $1", [i.id]); if (p.rows[0].stock < i.qty) return res.status(409).json({ error: "out of stock" }); total += p.rows[0].price * i.qty; } if (couponCode) { const c = await db.query("select pct, expires from coupons where code = $1", [couponCode]); if (c.rows[0] && new Date(c.rows[0].expires) > new Date()) total = total * (1 - c.rows[0].pct / 100); } const charge = await stripe.paymentIntents.create({ amount: Math.round(total * 100), currency: "usd", customer: req.user.stripeId, confirm: true }); const o = await db.query("insert into orders (user_id, total, status) values ($1, $2, $3) returning id", [req.user.id, total, charge.status]); for (const i of items) await db.query("update products set stock = stock - $1 where id = $2", [i.qty, i.id]); await mailer.send(req.user.email, "Order " + o.rows[0].id, "Thanks! Total: $" + total.toFixed(2)); res.json({ id: o.rows[0].id, total }); } module.exports = { createOrder }; ``` The team keeps breaking checkout when they change coupons or stock rules, and the code is hard to test. Review the architecture and present your findings as a single HTML report: the problems you see, the changes you recommend in order of value, and what the code would look like after the most important change.”
Skill commit
5beb35b
Without the skillWith improve-codebase-architecture
⇆
Without, runWith improve-codebase-architecture, run3 independent runs per side, none selected by hand.

Download the with-skill page

vercel-react-best-practices

React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.

Category
Frontend
Source
vercel-labs/agent-skills
License
Not stated
Proof model
claude-opus-5-5
Brief
“Here is a slow Next.js product list page. It fetches products, reviews and inventory one after another in a client component with useEffect, renders 500 product cards at once, imports the full lodash library, and re-sorts the list on every render. Rewrite it following current React and Next.js performance practice, and present the result as a single HTML page that shows the new code, explains each change, and estimates the impact of each.”
Skill commit
063bee9
Without the skillWith vercel-react-best-practices
⇆
Without, runWith vercel-react-best-practices, 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 improve-codebase-architecture or alternatives to vercel-react-best-practices.