Diagnose Sunday Miami same‑day outages

Instacart offers same‑day or scheduled delivery; same‑day is disabled when shopper supply is insufficient. Data show that on 2 of the last 3 Sunday afternoons in Miami, same‑day was disabled. a) Define precise supply–demand balance metrics: real‑time shopper‑to‑order ratio, fill rate within SLA, queueing delay distribution, shopper acceptance rate, and effective capacity after time‑to‑shop and travel constraints. Which single leading metric would you use to trigger disablement and why? b) Lay out a root‑cause tree with the exact data you’d pull (traffic by minute, batch creation rate, shopper online/active, substitution complexity, store closures, pay rates, weather, events), and how you’d separate demand spikes from supply drops causally (e.g., instrument with exogenous weather, difference‑in‑differences vs other markets). c) Propose 3 interventions (supply incentives, scheduled‑to‑same‑day rebalancing, demand shaping via ETAs/fees) and for each, design an experiment with eligibility, randomization unit, guardrails (cancellations, NPS), and success metrics; quantify expected impact and key risks (cannibalization, fairness, marketplace instability).