Evaluate smart cart idea and design experiment

Product/Experiment Case: Smart Cart in a Partner Grocery Store

Instacart is partnering with a local grocery store to introduce a smart cart.

Product concept

• While physically shopping in the partner store, a user can use the smart cart UI to:
  1. search/browse the current store’s products and prices , and
  2. simultaneously see products and prices from other stores on the Instacart app .

Your tasks

1. Is this a good idea? State your reasoning and key risks/tradeoffs.
2. Propose clear hypotheses (at least 2–3) about how this feature will impact Instacart’s marketplace.
3. Define a measurement plan:
   • Primary success metric(s)
   • Diagnostic metrics (to explain why it moved)
   • Guardrail metrics (to ensure no harm)
4. Design an experiment (A/B test or alternative) :
   • Unit of randomization (user, trip, store, cart) and why
   • Treatment/control definition
   • Key threats to validity (spillovers, interference, selection bias) and mitigations
   • How you would analyze results and make a ship/no-ship decision

Assume you can instrument cart events and link them to Instacart account activity, but the feature is only available in some partner stores initially.