To give him the benefit of the doubt maybe it was an artificial question and the real question is how do you make a large scale "cloud native" system say something like Netflix / Facebook.

Of course the problem with those systems is that it's very difficult to explain it in detail of every part in an interview so his example was just a small part of that system. Also most companies do not require that level of scalability but I concede they are fun to build just not very fun to maintain/operate.

I have no doubt that the architecture I described was something he had personally built as part of what he was doing at the company. Me questioning that was probably taken as an attack.

I never got the job or even a single word of feedback.