why did weekly active users drop to zero after onboarding: fix the missing activation events
Fixes weekly active users dropping to zero after onboarding by finding which activation events stopped firing in the new flow. Use when WAU reads zero for newly onboarded cohorts. Not for an onboarding flow that was intentionally replaced with a different metric.
TL;DR
New cohorts reading zero WAU while older cohorts stay normal means the new onboarding flow stopped emitting, renamed, or re-keyed the activation events the WAU query depends on. Compare the event stream of a user onboarded yesterday against one onboarded last month and the difference is the bug.
why did weekly active users drop to zero after onboarding: fix the missing activation eventsUse this when
- WAU is zero only for users onboarded after a flow change
- Older cohorts report normally
- The activation milestone events have new names, steps, or owners
Not for this skill when
- Onboarding was paused or signups were halted
- WAU dropped for all cohorts, pointing at the metric query itself
Steps
- Pick one user from a zero-WAU cohort and dump their full raw event history. Verify: every event they actually generated is visible, whatever it is named
- Do the same for a user from a healthy cohort and diff the two event sets. Verify: the missing, renamed, or re-keyed activation events are listed exactly
- Check the WAU and activation query definitions against the new event names and id fields. Verify: the query clauses that no longer match are identified
- Update the instrumentation or the query, then re-run WAU for the affected cohorts. Verify: new cohorts report non-zero WAU consistent with their raw activity
- Add a contract test that fails the release if a required activation event stops arriving from the onboarding flow. Verify: the next flow change cannot silently zero activation again
Variant phrasings
new cohort WAU zero
A related phrasing for the same underlying problem.
activation events missing after onboarding change
A related phrasing for the same underlying problem.
onboarded users not counted as active
A related phrasing for the same underlying problem.
Compatibility: Compatibility: onboarding instrumentation with analytics WAU definitions (warehouse or Mixpanel/Amplitude cohorts), current versions.
Why it happens
Cohort-specific zeros are a fingerprint: the metric works, the users exist, so only the newest flow's contract with the metric broke. A two-user raw diff is faster than any dashboard exploration because it shows what the new flow actually emits versus what the query expects.
Edge cases / pitfalls
- A new flow may emit events under a fresh anonymous id that never stitches to the account. Check identity resolution, not just event names.
- Backfilling cohort WAU from raw events is valid only if the raw events were captured. If the client never sent them, mark the gap honestly.
- Some flows delay activation events to a batch job. Confirm the batch schedule before declaring events missing.
Provenance
Resolved from the public thread: https://vectle.com/posts/pst_o97WArDXdKxKzQ4Uf7rQuQ