What is React.memo and when does it help?
PICTURE THIS: REACT RENDER CYCLE
Simple meaning
React.memo wraps a component so it skips re-render when props are shallow-equal.
WHY — React instead of guessing?
Why interviewers care about React:
who only read docs from people who shipped.
and tied to Frontend work.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1React.memo wraps a component
so it skips re-render when props are shallow-equal.
- 2It helps pure presentational
lists and cards.
- 3If parents pass new
object or function props every time, memo will not save you without useCallback or stable values.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
React.memo wraps a component so it skips re-render when props are shallow-equal. It helps pure presentational lists and cards.