# UI Performance Guard > Enforces Vercel-standard performance optimizations for React and Next.js applications. Use when this capability is needed. - Skill: `tomevault-io/ui-performance-guard` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/ui-performance-guard` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/ui-performance-guard/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Web & Frontend - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/ui-performance-guard --- # UI Performance Guard Enforces Vercel-standard performance optimizations for React and Next.js applications. ## Instructions ### 1. Eliminate Waterfalls (CRITICAL) - Defer `await` until the data is actually needed in the render tree. - Use `Promise.all()` for independent, concurrent data fetching. - Implement `Suspense` boundaries to unblock the initial paint of the shell. ### 2. Bundle & Tree Shaking (CRITICAL) - AVOID barrel file imports (`import { x } from "@/components"`); use direct paths to ensure proper tree-shaking. - Use dynamic imports (`next/dynamic` or `React.lazy`) for heavy components or those below the fold. - Audit third-party libraries; prefer native browser APIs over heavy dependencies where possible. ### 3. Render Optimization - Extract expensive computational work into memoized components or `useMemo`. - Use functional updates in `setState` (e.g., `setCount(c => c + 1)`) to avoid stale closure dependencies. - Deduplicate global event listeners and timers using `useRef` for persistence across renders. ### 4. Asset Management - Optimize SVG precision and minimize path data. - Use `content-visibility: auto` for off-screen components in long lists. - Hoist static JSX elements out of the render loop to prevent unnecessary re-allocations. ## Verification - Run `npm run lint` and check for performance-related warnings. - Verify that initial bundle size is within the project's performance budget. --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/infodungeon) — claim your Tome and manage your conversions.