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.