Explain-It-Back Quizzes
Use these prompts to test whether you can reason from first principles instead of memorizing platform terms.
Why is route rollback not automatically database rollback?
Strong answer
Route rollback changes which artifact owns traffic. Database rollback changes durable product truth and may be impossible or unsafe after migrations or writes.
Should mention
What survives process death in a Vango/Rhone app?
Strong answer
Product database state, control-plane operations, artifacts, route ownership, and explicitly persisted session/runtime state survive. In-memory session state does not.
Should mention
Why does horizontal scale require broadcast for global live state?
Strong answer
Two allocations have separate process memory. If global live state changes on one allocation, other allocations need a shared fanout channel or they render stale views.
Should mention
If edge cache, worker log, and control database disagree, which wins?
Strong answer
The durable control-plane record wins. Edge cache must refresh/replay from a verified snapshot, and logs explain but do not decide truth.
Should mention
Why can a sleeping GET be held but a sleeping payment webhook cannot be blindly replayed?
Strong answer
GET is idempotent enough to wait within a wake budget. A webhook/action can mutate external or product state and needs signature/idempotency/retry semantics.
Should mention
What can multi-region failover safely move first?
Strong answer
New sessions can route to eligible regions after data, runtime services, secrets, artifacts, and residency are ready. Existing live sessions stay pinned or reconnect as fresh/hydrated sessions by explicit policy.
Should mention