When Does Read the Docs Serve Stale HTML After a Successful Build?

Read the Docs renders HTML from Sphinx sources and stores build artifacts per project version and branch. Rendered pages are then served through a CDN that caches both HTML and static assets. The latest and stable aliases are mutable pointers to the most recent successful build, while versioned URLs such as /en/1.2/ are effectively immutable.

Because an alias changes target on each successful build, a previously cached page for latest can remain valid at an edge after the new build completes. Read the Docs does not expose a user-controlled purge for this layer, so freshness depends on build events, cache TTLs, and the CDN's invalidation behavior. Projects with frequent builds, multiple regions, or heavy reliance on the latest alias may see a wider window in which different users receive different content.

Which mechanism actually governs how long a stale latest page survives at a given edge? Does the versioned URL stay stable while latest lags, and how would that difference be confirmed across networks?