An expert guide to how the Next.js App Router renders and caches — static vs dynamic rendering and what triggers each, the four caching layers (Request Memoization, Data Cache, Full Route Cache, Router Cache), fetch caching in Next 15+ (uncached by default), time-based and on-demand revalidation with revalidateTag/revalidatePath, unstable_cache for non-fetch data, route segment config, streaming with Suspense and loading.tsx, and Partial Prerendering — with common mistakes and exercises.
A practical guide to making JavaScript fast — the single-threaded model and avoiding main-thread blocking, debounce and throttle, memoization, efficient DOM updates and batching, memory leaks and how they happen, garbage collection, WeakMap/WeakSet, and measuring with DevTools — with hands-on exercises and solutions.
A practical breakdown of Elementor's V4 Atomic Editor — Classes, Variables, the unified Style Tab, and the dramatically cleaner DOM — with a real before/after example and honest migration advice.