React composition patterns that scale. Use when refactoring components with boolean prop proliferation, building flexible component libraries, or designing reusable APIs. Triggers on tasks involving compound components, render props, context providers, or component architecture. Includes React 19 API changes.
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.
Use when implementing multiple related enhancements, or a large feature that must be split across risk boundaries, and you need to decide branch/PR structure. Covers accumulating related work on one shared branch with atomic commits per enhancement, splitting risky multi-PR features along risk seams, and safely handling a branch that has both committed and dirty (uncommitted) work when shipping.
Use when a rebase or merge reports conflicts on a file where both branches only appended or inserted new content (append-only logs, registries, holding-pen documents) rather than editing the same lines. Recognizes the conflict as a false signal and resolves it as a union-keep-both operation instead of a real semantic merge.
Use when reskinning an app with a real brand's visual identity — extract the actual palette from a live site's raw CSS (not markdown), recreate logo/icon assets programmatically with documented extraction rationale, and codify everything as versioned, named design tokens rather than one-off hardcoded values.
Use when building a skill, doc, or knowledge base for an existing internal service or codebase, or when asked to audit past sessions for recurring failures and gaps — mine prior Claude conversation transcripts instead of reverse-engineering from logs or current code alone.
Use when a Windows/Linux-mixed repo shows spurious linter "Delete ␍" warnings, gofmt/prettier flags files as unformatted after a clean rebase, or golden-fixture tests fail on byte-exact CRLF-vs-LF comparisons — normalizes line endings via .gitattributes rather than reformatting or skipping tests.
Use when a mockup, dashboard, or app needs light/dark modes and/or multiple brand palettes, or when asked to "reskin" or "retheme" an existing interface without touching its structure or interaction logic.