[itestyourcode]

I agree shaving dozens or hundreds milliseconds of latency is hardly noticeable to end users. But latency is an indicator of how well the system can perform and scale up. Signs of high latency under normal load can reveal design or implementation flaws in the software (supposedly running on any modern hardware) Ultimately you want a system can scale up and delivers consistent latency. Therefore, a low and consistent latency is a health-meter to assure that. Within the same cluster (no network I/O), Pulsar has pretty impressive 5ms pub/sub latency for persistent topics (including written to and acknowledged by the non-volatile disk)

[kjeetgill]

I agree with everything you're saying about the value of reduced/smoothed out latencies and I suspect the parent agrees with that as well, but the parent was mostly teasing about the choice of "business insights" in lieu of all you've mentioned.