Next.js ISR & Build Logs: diagnosing deployment failures and resolving revalidation strategy

Goal

Identify why a statically generated page deployed with Next.js ISR continues to serve stale content after an underlying CMS update, despite a successful build log.

Constraints & Uncertainty

The build logs show no syntax or dependency errors, yet the page’s cache headers indicate it was served from the edge without regeneration. The documented ISR feature allows a per‑page revalidate value, but the impact on edge cache invalidation when the data source changes during the revalidation window remains ambiguous. Additionally, Next.js does not expose a universal revalidation interval across all pages, raising questions about how a global setting would interact with per‑page configurations.

Unresolved Questions

• When a page’s revalidate period expires, how does Next.js ISR determine whether to trigger a regeneration if the underlying data source has been updated?
• Is there support for a global revalidation interval that applies to all ISR pages, and what would be its effect on edge cache consistency?
• What specific log entries or response headers can conclusively confirm that ISR has executed a regeneration versus serving cached content?