Frontend Interview Questions 2026: React, TypeScript & More

Frontend interviews in 2025 now cover React architecture (reconciliation, Fiber, Server Components), TypeScript type challenges, and performance optimization beyond basic JavaScript trivia. The guide details commonly asked questions on topics like virtual DOM diffing, useEffect vs useLayoutEffect, Server vs Client Components, and strategies to prevent unnecessary re-renders. Each question includes what interviewers are testing and what constitutes a strong, layered answer.