This is the talk I gave at Erlang Factory SF Bay Area 2014 yesterday on the instrumentation work I've been doing at AdRoll. It's Erlang focused, at least in part, but I intended it to contain more generally applicable, hard-won lessons/thoughts.

The slides are here if video isn't your thing: http://www.slideshare.net/BrianTroutwine1/10-billion-a-day-1...