On the flip side, I've also heard "low-latency" (or even "instant") to mean "within 30 seconds", as an upgrade from "the mainframe runs a batch job every hour (

On the flip side, I've also heard "low-latency" (or even "instant") to mean "within 30 seconds", as an upgrade from "the mainframe runs a batch job every hour (or day)". I don't think there's any way to consider a phrase like "low latency" without considering what you're talking about.