UI automation is necessary for accessibility

> It is extremely rare that you get the luxury of having the requests a day equally distributed across every second of the day.

Just to clarify for folks who haven't done this before: If you graph queries-per-second against time, for the vast majority of web-related services, you get a sinusoid with a period of 1 day, a fairly significant amplitude (relative to the average), and in most cases, the graph looks completely different on the weekend. You must provision for the daily peak and not the average, or else you will fall over. Load balancing, caching, and other middlebox technologies can make the graph a bit flatter (at the origin server), but it will still have a daily peak and you will still need to deal with it.

This is not only true for the origin server, but also for most if not all of its backends (and their backends recursively). You really only get flat QPS from batch jobs running continuously, and even those are often spiky in practice.