Interview Warm-ups
React mock interview
Two rounds, two very different games. Here's what to expect and the ground rules for each React mock interview round, before you're sitting across from an interviewer. Prefer to read first? See our React interview questions and the mock interview guide, then practice with React coding challenges.
Conceptual Round
Explain your reasoning, not just the answer.
What to expect
- ✓Questions on hooks, closures, re-renders, and state management
- ✓Follow-up "why" questions that probe your reasoning
- ✓Verbal / whiteboard explanations — no code editor
- ✓Real-world scenarios like performance bugs or stale state
Rules
- ✓No searching or AI tools — answer as you would live
- ✓Think out loud; silence reads as uncertainty
- ✓It's fine to say "I don't know" and reason through it
- ✓Depth over breadth — one well-explained answer beats five shallow ones
Machine Coding Round
Ship a working feature under a timer.
What to expect
- ✓Build a working UI feature from scratch (autocomplete, tabs, modal…)
- ✓60–90 minutes, real code editor, no boilerplate provided
- ✓Evaluated on functionality, code structure, and edge cases
- ✓Company-style prompts modeled after real rounds
Rules
- ✓The timer starts the moment you begin — plan before you type
- ✓No copy-pasting from docs or AI assistants
- ✓A working, imperfect solution beats an unfinished perfect one
- ✓Handle edge cases (empty, loading, error states) unless told otherwise
Coming soon
FAQ
Frequently asked questions
A React mock interview simulates a real interview loop for a frontend role — you get asked React-specific questions live, just like you would with a real interviewer, so you can practice explaining your reasoning under pressure instead of just reading answers. On ReactGrind, this happens as a spoken, conversational round rather than a written quiz.
A general coding interview usually tests algorithms and data structures in any language. A frontend mock interview focuses specifically on the skills a frontend or React role actually tests — component design, state management, rendering behavior, and building working UI under a timer — which is exactly what the Conceptual and Machine Coding rounds here are built around.
Focus on the concepts that come up in almost every React interview — hooks, re-renders, state vs. props, and common performance pitfalls — and practice explaining them out loud, not just recognizing the right answer on a quiz. Pairing that with hands-on problems (not just reading) is what actually builds interview-day confidence.
Expect a mix of conceptual questions (how hooks work, why a component re-renders, controlled vs. uncontrolled inputs) and hands-on building tasks (implementing a feature like a todo list, autocomplete, or modal from scratch). Company-style interviews often combine both in a single loop.
React machine coding means building a real, working UI feature from scratch under a timer — think autocomplete, tabs, or a modal — evaluated on functionality, structure, and edge cases. It's different from LeetCode-style algorithm problems, which test data structures and logic in isolation rather than actual UI engineering.
The Conceptual Round is a Pro feature. If you're not on Pro yet, you can upgrade from the Pricing page — the Machine Coding Round is still being built and will be announced here once it's ready.