Next.js · Caching · Tech Lead · Debugging
Lead: production shows intermittent stale dashboards. How do you diagnose?
Short Interview Answer
Map which cache layer, check personalization leakage, verify revalidation hooks, add cache telemetry, and fix defaults with tests.
Detailed Explanation
Reproduce with cache keys and cookies. Confirm CDN vs app cache. Establish runbooks for purge. Treat cache bugs as P0 when auth data leaks.