So, what is the killer app of faas? To my layman understanding the selling point is easy scale-ability, but it seems to be inherently at odds with serverless being the most expensive computing model?
Not necessarily; what matters is how peak-y the demand is. For example, my country's teachers portal gets orders of magnitude more requests during a couple of weeks of the year than the average (at the start of the school year). Going serverless for those processes might make sense.
