Discuss caching mechanisms available in next js?

Here's a high-level overview of the different caching mechanisms and their purpose:

By default, Next.js will cache as much as possible to improve performance and reduce cost. This means routes are statically rendered and data requests are cached unless you opt out.

1
Request Memoization
2
Data Cache
3
Full Route Cache
4
Router Cache

Difficulty: 5/10

Topics: Static Generation, Incremental Static Regeneration, Edge Caching

Scenario Questions

0-2 years experience

1
You need to pre‑render a blog post that rarely changes. Which Next.js caching feature would you pick and how would you set it up?
2
If you add a Cache-Control: max-age=0, must-revalidate header to a page, what effect does it have on the browser and Vercel edge cache?

2-5 years experience

1
The product team wants the homepage to refresh its data every 10 minutes without redeploying. How would you achieve that with Next.js caching, and what trade‑offs are you making?
2
During a load test you notice an API route recomputes its response on every request. Walk me through how you would add caching to that route and verify it works.

5-8 years experience

1
Design a caching strategy for a multi‑tenant SaaS dashboard built with Next.js that serves public marketing pages and private user data, considering ISR, edge caching, and server‑side fetching.
2
Stale data is being served from Vercel’s edge cache after a recent database migration. How would you diagnose the issue and correct the caching configuration?
3
Compare ISR with on‑demand revalidation for a high‑traffic news site. Discuss performance, cost, and data‑freshness implications.

8+ years experience

1
Our organization is consolidating several legacy Node services into a Next.js monorepo. How would you define a unified caching policy that balances SEO, data freshness, and cross‑team deployment cadence?
2
When scaling to global traffic, what architectural changes would you propose for Next.js caching layers (edge, CDN, server) to minimize latency while keeping data consistent across regions?
3
We currently use a custom Redis cache for server‑side data. How would you evaluate migrating to Next.js built‑in caching primitives without breaking existing contracts?

Follow-up Questions

❓What happens if you set the ISR revalidation interval too low?
❓How does your caching choice impact SEO for pages that fetch data at request time?
❓How would you monitor cache hit‑rates and detect stale data in production?