3-6y

Web Performance and Browser Security Basics

Performance means the site feels fast and stable. Security means the browser should not trust the wrong content.

Analogy

A good school gate should be wide enough for quick entry and strict enough to stop strangers from entering the classrooms.

Follow-up questions

Topic practice prompts

What frontend performance and security topics do you consider must-know for interviews?

Performance: web vitals, bundle size, rendering cost, caching. Security: XSS, safe HTML rendering, token handling, and browser trust boundaries.

  • How would you reduce LCP?
  • When is dangerouslySetInnerHTML acceptable?
Cheat sheet

Last-day revision lines

  • LCP-style thinking: main content speed.
  • Responsiveness depends on main-thread availability.
  • Avoid layout shift.
  • Sanitize untrusted HTML.
Source references
  • Web performance and security: context/Web perfomance and security.docx
  • HTML CSS JS questions: context/100 important HTML, CSS, and JavaScript interview questions.pdf
Offline study support

Local resource packs for this topic

1 local packs

Use these local packs when you want broader official-source context without leaving the app.

performancePerformance and Web Vitals

Performance and Web Vitals

A local digest of high-value web performance ideas that connect directly to React and product interview rounds.

Performance and SecurityReact.jsFrontend Breadth

Web vitals, LCP thinking, responsiveness, layout stability, render cost, bundle strategy, and main-thread awareness.

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Next step

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