intermediate
Browser performance
Core Web Vitals, lazy loading, code splitting, resource hints, caching, and measurement-first optimization.
Browser performance interviews connect user-visible metrics to delivery choices: vitals, deferred loading, bundle shape, hints, and cache strategy.
Subtopics: Core Web Vitals, lazy loading, code splitting, resource hints, and browser caching.
On interviews: explain LCP, CLS, and INP causes, when lazy loading hurts the hero, and preload versus prefetch.
Common pitfalls: lab-only optimization, lazy hero images, and cache headers that trap deployments.
The trade-off is convenience versus control — pick the mechanism that matches your coupling and performance budget.
Checklist:
- Measure field data, not only Lighthouse.
- Protect LCP and interaction paths.
- Split bundles by user journey.
- Version caches and plan invalidation.