PJ / DEEPBRAINInterview decision lab
STUDY GUIDE · 23 OCT 2026
deepbrain.define-labs.com
Practice / PERSONAL STUDY · PUBLIC, SYNTHETIC & PROPOSED LABELS APPLY

THE MAIN POINT

Which cohort merits customer-success investigation?

0s

Uses your device's speech voices. No paid API. Test your speaking pace aloud.

E04 · Mature repeat value

Synthetic practice, not company performance.

One decision

Which cohort merits customer-success investigation?

Run the exact query

WITH b AS (SELECT * FROM v_user_cohort WHERE ('all'='all' OR persona='all') AND ('all'='all' OR primary_workflow='all') AND ('all'='all' OR substr(signup_at,1,7)='all') AND date(signup_at)>='2026-05-01' AND date(signup_at)<'2026-10-01') SELECT cohort_month,COUNT(*) eligible_users,SUM(return28_41) returning_users,100.0*AVG(return28_41) return_pct FROM b WHERE mature42=1 GROUP BY cohort_month ORDER BY cohort_month;

Download SQL · Result CSV · Metabase saved question

Chart and reading

Synthetic practice chart

Use the complete days 28–41 window, counts and cohort mix.

Challenge your recommendation

Are later cohorts censored or jobs naturally infrequent?

Guardrails: Unconditional signup return during days 28–41, not retention conditional on activation.

Next evidence: Interview returning and nonreturning users about need frequency and unobserved offline use.

PRD sections: 3, 14, 17. Open proposed PRD

Your spoken decision

State one takeaway, one caveat and one action in 30 seconds. Then stop.

Connect this finding

What this chart helps decide · Follow the connected decision · Canonical metric definitions

Optional model answer — try your own first

E04 · Mature repeat value

Decision: Which cohort merits customer-success investigation?

Readout: Use the complete days 28–41 window, counts and cohort mix.

Actual query output (synthetic), first rows:

cohort_month eligible_users returning_users return_pct
2026-05-01 52 5 9.615384615384617
2026-06-01 51 14 27.450980392156865
2026-07-01 56 7 12.5

Model spoken answer: I would investigate mature cohorts with weak repeat value, after checking their job frequency and coverage.

Caveat/counterargument: Are later cohorts censored or jobs naturally infrequent? Unconditional signup return during days 28–41, not retention conditional on activation.

Next evidence: Interview returning and nonreturning users about need frequency and unobserved offline use.

Deliberately left out: A claim that return equals satisfaction or learning.

All exercises

Your practice notes

Write your answer first. Notes autosave locally; reading completion does not judge correctness.

Study tools