Client and Server Views of the Same Call

A server that never received a request cannot tell you the user tapped send and the client failed before dialling. A client that logged a 200 cannot tell you the payload was empty or stale.

Correlate with a shared request identifier whenever you can. When you cannot, align clocks and release versions carefully, and state the uncertainty in the report.

For in-app usage work we often find the largest blind spots at the edges: offline queues, background refresh, and partner SDKs that emit traffic without product-visible events.

Ask which decisions require client evidence, which require server evidence, and which need both. That question alone trims half the vanity dashboards.