Good to know: Check if your upstream data provider has caching enabled by default. You might need to disable (e.g. useCdn: false), otherwise a revalidation won't be able to pull fresh data to update the ISR cache. Caching can occur at a CDN (for an endpoint being requested) when it returns the Cache-Control header. ISR on Vercel persists the cache globally and handles rollbacks.
On-demand Revalidation
If you set a revalidate time of 60, all visitors will see the same generated version of your site for one minute. The only way to invalidate the cache is if someone visits the page after the minute has passed.
The Next.js App Router supports revalidating content on-demand based on a route or cache tag. This allows you to manually purge the Next.js cache for specific fetches, making it easier to update your site when:
Content from your headless CMS is created or updated.