Are you arguing that setting up QoS metrics for a search engine index is intrinsically hard in the way that monitoring the safe running of a nuclear power plant

Are you arguing that setting up QoS metrics for a search engine index is intrinsically hard in the way that monitoring the safe running of a nuclear power plant or an air traffic control system is not? I think maintaining a search index is intrinsically hard - much like maintaining a nuclear power plant. I don't think monitoring a search index is though. I'm also skeptical of the notion that the engineering of the search index has changed fundamentally in the last 5 years. Realistically Google is not under much competitive pressure any more.