8 April 2026 · Stability

Crash-free sessions are not a DAU costume

Daily active users can rise on the same morning a build starts failing before the first frame. If stability lives on another slide, nobody has to notice.

DAU is a headcount of devices that opened something. Crash-free sessions is a quality claim about those opens. When the two use different session definitions, you can grow the headcount by counting process starts while hiding the crashes that happen before UI. Product celebrates. Support does not.

Session Health Desk exists because engineering dashboards and product dashboards in UK consumer apps often refuse to share a midnight. We put both numbers on the Signal Ledger, same clock, same exclusion rules. If crash-free cannot fit, activation does not get to wear a crown that week.

Older Android is not a footnote

Averages lie toward flagship devices. A regional rail companion we studied looked elite until we split crash-free by OS band. The older band was the commuter band. Staffing a polish sprint for the newest phones would have been a category error.

ANRs belong in the family

An ANR is not a crash, and users do not care about your taxonomy of failure. If the ledger only has room for one stability figure, pick the one your support tickets describe. Then footnote the other. Do not let a vendor’s default “crash-free users” (a different denominator again) wander into the pack unannounced.

Read the Signal Ledger method if you want the ritual, or the rail case if you want the bruise.