Engineering
Fixing Next.js ISR Cache on Cloudflare
How TentUI's daily GitHub-star revalidation exposed a read-only OpenNext cache.
SS
Sourabh SoniUpdated July 25, 2026
The failure
TentUI's GitHub star count is cached for one day. When that cache became stale, production requests started failing because the OpenNext setup could read build-time assets but could not write regenerated entries or coordinate revalidation.
The fix
The site combined time-based revalidation with a read-only incremental cache and no production-ready queue. The fix was to use R2 as the writable incremental cache and an OpenNext Durable Object queue to coordinate regeneration.
Read the full investigation
The complete article covers the production evidence, failure chain, corrected Cloudflare configuration, and stale-to-fresh verification process.