JavaScript and React Lead Interview

What they ask

Front-end hiring runs: phone screening by HR, an HR interview, a technical test, a technical interview with the front-end lead centered on JavaScript and React, and a separate interview with an engineering manager on problem solving and logical reasoning.

Questions in this area with the lead, for example:

• JavaScript: closures and the module pattern; this in arrow vs regular functions; the event loop and promise ordering; debounce vs throttle and when a search box needs which.
• React: what triggers a re-render and how to stop unnecessary ones (memo, useMemo, useCallback, stable keys); useEffect dependencies and cleanup; lifting state vs context vs a store; controlled vs uncontrolled inputs.
• Live exercise: build a doctor search input that calls an API as the user types, with debounce, loading and empty states, and cancellation of stale requests.
• Performance: code splitting, lazy routes, image loading, and how you would measure a slow list page.

The technical test before this round is a short front-end assignment or an online quiz on the same topics.

What they look for

• Explaining the render model precisely rather than reciting hooks.
• A working, readable solution to the live exercise with edge cases (fast typing, request ordering).
• Practical performance instincts and knowing what to measure first.