title: what percentiles metrics reflect your app performance?
body: <p>I've been recently introduced to the percentile metrics for measuring different aspects of your application's efficiency (i.e: like p50, p90, and p99 latency, etc..)
  I'm not sure why are p50s used, like this kind of metrics is sort of vague and doesn't provide much of information in case you wanted to measure your app's efficiency.
  I think this might be a broad question, but what kind of percentiles reflect the most about the efficiency of your app ?</p>