The chairman track 🏛️ · for the chairman, C-level and board · 3 x 45 min · no code to write
Decision mode: why a three-month window hides a strategic break, what five years of the platform's own numbers say went right and wrong and what each finding cost, and the decisions that follow - each with an owner, a metric, a review date and a pre-mortem.
Five years in one picture
Why a three-month window cannot tell a step from a wobble, the platform anatomy and the grain question, and the nine-angle map with a decision on every row. Drive the lookback window on real numbers.
🩺 Chairman 2 · mediumWhat went right, what went wrong
The break (cost, not price or volume), its running price, the two-quarter lag into customers and merchants, then the turn: customisation retains, bundles unsold, the catalogue moved.
🧭 Chairman 3 · mediumDecisions and the data we owe ourselves
Ownership map of every gap, then three tables - business, tech, data to collect - each row with an outcome metric, an owner, a review date and a pre-mortem line. The 90-day plan.
The analyst track 🛠️ · for data analysts · 5 x 45 min · pandas + matplotlib + lifelines, notebook per session
Build mode: map the data before reading it (a1), follow the margin to the mechanism and price the decision (a2), walk the product hierarchy and the baskets (a3), measure merchants and stores with survival analysis and activity rules (a4), and compute customer retention with frozen history, test the two-event confound, and export the canon numbers the chairman deck quotes (a5).
Map the data before you read it
Grain and join map, the coverage heatmap, key integrity by year, the duplicate scan that names a bad migration, and the question-availability table.
📉 Analyst 2 · mediumFollow the margin
Whole platform then one panel per server, indexed volume vs margin, the per-SKU bridge, rolling z change-point, seasonality, and the running price of the 2024 decision.
🧺 Analyst 3 · mediumProducts and baskets
Category share, line slope, SKU Pareto, platform vs merchant margin, pairwise lift in pandas, attach rates, basket size, preference per merchant, the price ladder.
🏬 Analyst 4 · hardMerchants and stores
Acquisition by year, growth accounting, Kaplan-Meier survival and the hazard jump, existing vs active stores, concentration, vintage curves, and the indicators that saw churn in month three.
🧊 Analyst 5 · hardestCustomers, promotions and the gaps
Frozen-history cohort triangles, the repeat-rate lag, the two-event confound, customisation retains, the promotion double edge, a 69-day funnel, growth accounting, and canon.json.
The dataset is synthetic and seeded: data/generate_data.py reproduces every CSV byte for byte, and its docstring lists the planted truths the notebooks recover. Retention numbers follow the forward-looking, frozen-history practice taught in depth in learn customer retention with phoebe.
Your passport 🎫
Clear all three quiz questions in a session and it gets stamped. Stamps live in this browser only.
The knowledge map 🧠
Both tracks at a glance - hover a session to spotlight its concepts, click any node to jump in.