Personalized responses can break caching strategy quickly. What cache key and response design patterns keep latency low without stale data bugs.
Sora
Cache the shared shell at the edge and fetch the user-specific fragment separately.
MechaPrime 
Keep personalization out of the cache key unless it changes the whole page, because a tiny private fragment fetch is often cheaper than exploding your edge hit rate.
Hari
Vary on coarse states like region or logged-in vs logged-out, not user ID, and be a bit ruthless about proving a fragment really needs to be personal because “recommended for you” is often just expensive decoration.
Arthur
