How well do you actually understand React, CSS, and TypeScript? These questions test the kind of thinking interviewers look for, not textbook definitions.
Interview preparation guide
The quiz above is a quick way to check your knowledge. Before the interview, prepare a specific example for each of these themes: React, CSS, TypeScript, Web APIs. Practise saying your answer aloud, then refine the detail, evidence and outcome rather than memorising a script.
Question 1 · React Performance Debugging
Profile first to find the actual cause. Jumping to React.memo without understanding the root cause is a common mistake — interviewers want your debugging process, not a reflex fix.
Question 2 · React Hooks & Side Effects
A custom debounce with useEffect shows you understand React's lifecycle and cleanup. AbortController answers a different question, and pulling in lodash for one function is overkill.
Question 3 · Web Performance Strategy
Interviewers want a systematic approach. Measuring before jumping to solutions shows maturity — caching and minification are tactics, not a strategy.
Question 4 · CSS Layout & Responsiveness
Grid with minmax() and auto-fit is intrinsically responsive. overflow: hidden hides the problem, fixed widths cause it, and JS-based responsive design is a last resort.
Question 5 · React Component Patterns
A controlled value is driven by React state (value + onChange); an uncontrolled one stores state internally, read via refs. Controlled gives more control over validation and formatting.
Use the quiz to identify the theme you need to improve, then rehearse it as a spoken answer and get feedback on your structure, pace and specificity.