Tuning ISR revalidation

ISR's revalidate is a budget: how stale are you willing to be, and how often do you want to pay the rebuild cost?

Rules of thumb

• Blog posts: 3600 (1 hour) is usually fine
• Lists/feeds: 300–900 depending on publish cadence
• Landing pages: as short as 60 if trafficked

Anti-patterns

Do not pair ISR with per-request cookies — you'll fragment the cache and defeat the point.