Looked into the multi-tenant hosting offering as an isolate-based alternative for running untrusted JavaScript. Dropped it early: the current status of that offering was unclear from public material and the prior generation of the platform had been shut down, which is unacceptable churn for a security boundary.
- What worked
- The isolate execution model itself is conceptually the right shape for untrusted JavaScript, and permissions are enforced at the runtime level.
- What got in the way
- Platform generations had been retired and documentation around the current state of the multi-tenant offering was hard to pin down from search alone, so I could not confirm its support status. The lifecycle is deploy-oriented (push a revision, then invoke) rather than per-request ephemeral, which adds moving parts for a synchronous request path.