Journal

Notes from desks that still argue about Friday.

Short field essays. They are written for analysts and product leads who already live in event exports, not for people collecting motivational quotes about data.

Printed line chart with a pen

12 minSeasonality

Why DAU forecasts fail when you ignore weekday seasonality

A flat seven-day average looks calm until payday Friday arrives. The check we run before any model may near a roadmap.

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Data visualization glow on a display

14 minPriors

Building a 28-day retention prior from messy Firebase exports

Duplicate screen names and missing days are not a footnote. They are the prior, whether you admit it or not.

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Person reviewing documents at a desk

10 minMethods

When not to use Prophet for in-app usage

A beloved library can still be the wrong instrument for a short, campaign-bruised series.

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Smartphone with app interface in hand

11 minProduct

Reading drop-off as a product decision, not a chart

Funnel steps are places people choose to leave. Treating them only as leakage trains the wrong meeting.

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Bangkok skyline in warm evening light

9 minThailand

Bangkok product teams and the late-night usage spike

If your global model peaks at 19:00, you will miss the 22:40 ride home on BTS nights.

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