Build-time fetching handles most third-party data on a static site. It falls down in one specific case: content that should change on a schedule you are not rebuilding on. A page showing twelve rotating items each day, with a weekly deploy cadence, cannot get its data from the build.

The naive fix puts a fetch in the browser. Every visitor then hits the upstream API directly, which burns through rate limits, exposes any key you are using, and leaves the page empty when the provider has a bad afternoon.

Most tutorials that put third-party API data on a static site reach for client-side JavaScript. The page loads, a fetch runs, and content appears a moment later. It works, and it throws away most of what a static site is for. Search engines see an empty container, every visitor costs you an upstream request, and a rate limit or an outage at the provider becomes a broken page for everyone.