Backend-only view annotating every known scaling ceiling on the Cloud Run
estate. Red = single-point limits with no horizontal path today.
Yellow = scales, but into a cost or quota cliff. Green =
horizontally scalable today.
The Cloud Run migration removed several former ceilings outright: there
is no NAT port pool to exhaust, no single-replica pinned deployments, and
the video generator’s old in-memory job queue is gone (each render is its
own Job execution, retried by the owning workflow).
The remaining red items are key-shaped, not compute-shaped: one
matchmaker signer, one attestation signer, a finite funded-keypair pool
for AI opponents. Scaling them means key management work, not more
instances.
MCP session stickiness is a managed trade-off: client-IP affinity keeps
Streamable HTTP sessions on one instance; the preimage mirror in
Firestore bounds the blast radius of a restart to a re-read, not lost
games.
Quota cliffs are watched via structured logs + log-based metrics (Cloud
Logging); the subsidy cap is an intentional economic brake, not an
accident.