The Retention Ledger
An eight-week directed study of cohort architecture, windowing accidents, and the politics of North Star metrics.
Folio 08 · Collier’s End · App analytics
The product speaks in events.
Endpoint Cachecore is a small British house for people who must explain what an application actually did — not what last quarter’s dashboard implied.
Continue to the programmes
19product organisations taught since 2019
6 wksdirected cohort, not a weekend certificate
73event dictionaries reviewed in-house
From the Ledger Room
“The cohort-window module stopped our weekly stickiness chart. We still miss the pretty line. The board paper is finally true.”Priya Nair · Head of Product, Leeds insurtech
Open programmes
Four rooms. One flagship ledger.
A Taxonomy You Can Defend
Event names that survive legal review, finance questions, and a product manager who likes synonyms.
Funnel Integrity
Rebuild conversion stories from raw events when the default funnel has been quietly double-counting retries.
How the house teaches
Judgement before tooling.
We do not tour Mixpanel, Amplitude, or a warehouse UI as if the interface were the craft. Students bring a live event stream — or a redacted extract — and learn to argue about identity, time, and what a “user” even is.
Sessions mix a short lecture with a written critique. You leave with a ledger, not a slide about “insights.” If your organisation still reports DAU as a success metric, we will be polite, then unhelpful to that habit.
What you practice
Three disciplines
Windowed retention that survives daylight-saving and weekly seasonality. Event contracts that product, data, and counsel can all sign. Funnels rebuilt from first principles when the vendor default has been flattering you.
A fragment from Reviews
The meal-kit that retired stickiness.
A United Kingdom meal-kit product had reported “weekly stickiness” for eleven quarters. After the Retention Ledger, the team published a four-week cohort ledger to the board instead. Orders from returning households were lower than the old chart suggested, and the marketing calendar changed the following month.
They did not enjoy the first paper. They kept the format. The longer reports live here.
Private correspondence
Write before you enrol.
If you are unsure whether your event stream is ready, send a short brief. We will say no when the work would be theatre.
Open the contact folio