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.