Brief
Record a 20-minute ML-case mock on the churn/LTV packet: selection/CV/leakage, PR-AUC/SHAP/threshold defense, plus two follow-up grillings.
Dataset
Churn/LTV case packet (train/holdout + leakage trap column + cost matrix).
Starter guardrails (plan 88)
Mock template; recording checklist; written self-grade within 24 hours.
100-pt rubric
Case solution 30; calibration + threshold defense 30; SHAP story 20; follow-ups 20.
Deterministic checks -> LLM review
Checks: recording present; threshold sweep table attached; self-grade filed. LLM review grades decision framing and trap handling.