Performance
12 posts tagged #performance on DiCodeWeb, from fundamentals to production, newest first.
12 postsUpdated Sep 17, 2026
Web Workers aren't magic for every slow page. This post covers when moving work to a worker pays off, what structured clone really costs, transferables, SharedArrayBuffer and COOP/COEP, a hand-written Comlink-style RPC, bundler setup, worker pools, cancellation with AbortSignal, real examples and alternatives like scheduler.yield.
What happens to an LLM feature once real traffic arrives: where latency actually comes from, a per-feature token and cost meter with tenant budgets, structuring prompts for provider prompt caching, exact and semantic caching, model routing, trimming context, batch APIs, parallel calls, retries with fallback and circuit breakers, and the dashboard I watch.
How streaming HTML works at the protocol level, where to put Suspense boundaries, avoiding waterfalls, selective hydration, Partial Prerendering in Next.js 16, the effect on TTFB, LCP and CLS, proxies that silently buffer your stream, and handling errors after a 200 has already gone out.
The three metrics Google uses to measure real user experience: how they're measured and calculated, why they matter for SEO, and a concrete process to find the real cause before you fix anything.
A correct mental model of the browser event loop — tasks, microtasks, frames — tested with predict-the-output puzzles, then used to explain why UIs freeze and how to chunk work, yield to the main thread and move heavy work to a Web Worker.
Building a virtual list in React + TypeScript by hand: windowing math with real numbers, overscan, variable heights with prefix sums and binary search, measuring with ResizeObserver, preventing scroll jumps, accessibility — and when not to virtualize at all.
What React Compiler actually does, the Rules of React it relies on, the ESLint plugin, incremental rollout with annotation mode and "use no memo", what to do with existing useMemo/useCallback, how to verify it works, common bailouts, third-party libraries and build cost.
How fonts affect LCP and CLS, choosing font-display, preloading the critical font, subsetting with unicode-range for Vietnamese, variable fonts, self-hosting versus CDNs, fallback metric overrides and next/font in Next.js.
A practical guide to shrinking the JavaScript you ship up front by combining route-level and component-level lazy loading.
What makes a component re-render, why a re-render isn't a DOM update, how to measure with the React DevTools Profiler, the real cost of memo/useMemo/useCallback, splitting context, colocating state, keys in lists, and how the React Compiler changes the picture.
Which format to pick, how srcset and sizes let the browser choose, when to lazy-load and when not to, reserving space to avoid CLS, image CDNs, art direction with picture, and using next/image in Next.js 16.
The performance wins and day-to-day developer experience improvements that made Bun my package manager of choice.