Product & Analytics / Performance & Reliability
Crash-Free Rate ~ (also "crash-free users", "crash-free sessions", "stability rate")
The share of users (or sessions) that did not experience a crash.
The fork, why two teams get different numbers
The DENOMINATOR unit and the definition of "crash." UNIT: crash-free USERS (distinct users with no crash / distinct users) vs crash-free SESSIONS (sessions with no crash / sessions).
In the Metric Library
- The full fork, both definitions worked all the way through
- The trap that makes the number lie, on a real export
- Every formula variant, spelled out
- The reconciliation anchor, what to tie it to and when to refuse
Reference: Mobile crash-reporting convention (no governing body); iOS/Android crash · ANR · and watchdog-termination classifications cited as reference