I spent a miserable afternoon a while back debugging a production issue where a user's private financial dashboard was showing cached data from a completely different account. Why? Because Next.js 14 decided that a standard, innocent-looking fetch() call should be cached aggressively until the end of time unless you explicitly went out of your way to block it.
It was the ultimate frontend footgun.
Thankfully, the ecosystem listened. With the recent maturity and widespread production adoption of Next.js 15 and the latest 16.x patches, the Vercel team completely flipped the script. Caching is now opt-in by default.
If you haven't audited your full-stack data fetching patterns lately, the era of pulling your hair out over stale data is over—but it means you need to adjust how you write your data layer today.
The Nightmare of "Everything is Cached"
