Make pages fast — Core Web Vitals and what actually moves them
Web performance the way interviews and real audits demand it — the Core Web Vitals (LCP, CLS, INP) and their decomposition, the critical rendering path, loading strategy (defer/async, preload and priorities, lazy loading done right), HTTP caching semantics (max-age vs no-cache vs immutable, CDN vs browser split), image and font optimization, JavaScript cost (long tasks, code splitting, hydration), rendering performance (layout thrashing, compositor animations), and measurement discipline (lab vs field, percentiles, attribution). Grounded in web.dev, MDN, and the HTTP specs. Part of the Developer track.
• Meets you at your level — never too easy, never too hard.
• Adapts every question to how you’re doing.
• Tracks your level over time. Skill practice, not a test.
All exam, test, and product names and trademarks are the property of their respective owners and are used here for identification and reference only. Keentune is independent study practice — not affiliated with, authorized, or endorsed by any of these organizations.