Notes & Essays

A home-only overlay, sessionStorage (not localStorage), useSyncExternalStore, Motion's AnimatePresence, and a CSS flag so the hero does not finish animating under the loader.

XSS, cookies, CSRF, CORS, CSP, and lockfiles — what React and Vue already escape, where v-html and dangerouslySetInnerHTML still bite, and how that maps onto App Router and Nuxt.

Call stack, microtasks, closures, this, and prototypes — then the TypeScript you use every day: narrowing and discriminated unions. Why it behaves that way, not just the syntax.

A custom font is a family name plus real files for each weight. The browser only uses bold, medium, or italic if you registered those faces — usually as WOFF2 via @font-face.

Share state across related UI pieces without prop wiring — and when a single component or shadcn is still the better choice.

Both run after render, but timing decides whether the user sees a flicker. Start with useEffect; reach for useLayoutEffect only when you must measure or sync layout before paint.

Reconciliation is how React compares the next UI tree with the previous one so it can update the real DOM as little as possible.

Re-renders are normal. Unnecessary ones usually come from unstable props, broad state, or overused context — fix the cause before sprinkling memo everywhere.

Controlled inputs keep form data in React state. Uncontrolled inputs keep it in the DOM. Prefer controlled for app forms; use uncontrolled for simple cases and file inputs.

memo caches a component, useMemo caches a value, useCallback caches a function. Use them together when prop identity matters — not on every line of code.