How should global state be designed in a large MERN frontend?
PICTURE THIS: STACK VS QUEUE
Simple meaning
Keep server state in a cache such as React Query and UI state in local component state.
WHY — React instead of guessing?
Why interviewers care about React:
who only read docs from people who shipped.
and tied to Full Stack 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:
- 1Keep server state in
a cache such as React Query and UI state in local component state.
- 2A global store holds
true client-only data such as wizard steps or unsaved drafts.
- 3Duplicating API data in
Redux without a cache policy is how apps go out of sync.
- 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
Keep server state in a cache such as React Query and UI state in local component state. A global store holds true client-only data such as wizard steps or unsaved drafts.