I largely agree with this. I didn't take "one server" literally; more as hyperbole. Concern about availability is overblown, not irrelevant! There are shades

I largely agree with this. I didn't take "one server" literally; more as hyperbole. Concern about availability is overblown, not irrelevant! There are shades of gray, though. Most sites don't need to engineer their system to hide catastrophic database failures from the user. Not being able to tolerate a single web server failure, though... that's just careless, and will end up giving you a bad reputation. You probably don't actually need five nines -- but three probably won't go amiss...