[Arnt]

Pay attention, and don't confuse intention with effect.

What she's saying is that if you configure scaling such that it'lll scale down when demand is unusually low, and then demand returns, the spike may be a difficult one to handle, particularly if your services depend on each other but each scales only based on its own history.

If A needs B needs C, and demand suddenly returns to A, does that cause C to scale up? Or will A scale up first, and but C stay low for another half-hour because it recently scaled down?

Having C stay under demand for a half-hour after an outage ends wasn't anyone's intention when the autoscaling was configured. But as I wrote, don't confuse intention with effect.