Except she writes: " Then it does its weird userspace "thread" flip back to the original request's context and reads the response. It chews on this data, because, again, it's terrible JSON stuff and not anything reasonable like a strongly-typed, unambiguously, easily-deserialized message. The clock is ticking and ticking. "

If she laments that it is bad design to do the deserialization on the IO thread it is just as true for JSON as it is for protobuf or whatever "true rpc" format she considers worthy.