Performance APIs: Web Vitals, Long Tasks, and Real Metrics
Understand the browser APIs behind performance measurement: PerformanceObserver, long tasks, navigation timing, and capturing Web Vitals in real apps.
Practice
Use the blog to sharpen answers, review weak areas, and move from basics to mock-style prep without guessing what to read next.
Resume Prep
Jump back into the roadmap you already started, or use the article filters below to practice a specific topic.
Start with JavaScript Core and build your path from basics to mock review.
Basics build confidence, practice sharpens answers, and the roadmap keeps you moving toward the next interview topic.
If you want a guided path (instead of random reading), pick a roadmap. Each one is ordered top-to-bottom.
Event loop, closures, this, hoisting, async, and the fundamentals interviews test.
Types vs interfaces, narrowing, generics, utility types, and practical TS patterns.
Rendering, hooks, state, effects, performance, and common production patterns.
Semantics, layout, flexbox/grid, responsive design, accessibility, modern CSS.
The first lesson in each roadmap — great if you want a clean entry point.
A practical, interview-focused guide to the JS event loop: call stack, Web APIs, task queues, microtasks vs macrotasks, and common trick questions with real examples.
A deep, interview-ready guide to TypeScript types vs interfaces: extension, unions, intersections, declaration merging, and practical patterns for real codebases.
Filter Your Practice
Search by concept, narrow to a series, or pick a tag to focus on the exact topic you want to rehearse.
Results
Understand the browser APIs behind performance measurement: PerformanceObserver, long tasks, navigation timing, and capturing Web Vitals in real apps.
A high-signal mental model for LCP, INP, and CLS: what they measure, what actually moves the needle, and how to debug them in real apps.
A deep, interview-ready accessibility guide: semantic HTML first, ARIA rules, focus management, keyboard support, and common mistakes that break screen readers.
A deep, practical guide to Core Web Vitals for frontend interviews: what LCP/CLS/INP measure, common causes, how to debug in DevTools, and high-impact fixes.
A deep, practical guide to Service Workers: lifecycle, caching strategies (cache-first, network-first, stale-while-revalidate), offline support, and common pitfalls.
A deep, interview-ready guide to HTTP caching: Cache-Control directives, ETag/If-None-Match, Last-Modified, CDN caching, and how frontend apps should leverage caching safely.
A deep, interview-ready guide to how browsers render pages: DOM/CSSOM, render tree, layout (reflow), paint, compositing, GPU layers, and practical performance fixes.
A deep, interview-ready guide to CORS for frontend developers: preflight, simple requests, credentials, cookies, SameSite, and how to debug common failures.
A deep, interview-ready guide to browser storage: cookies vs Web Storage vs IndexedDB, quotas, security pitfalls (XSS), JSON patterns, and best practices for modern frontend apps.