Practice — Case Study: Design a Mobile App From Scratch (5 questions)

Interview prompt, live, 30-40 minutes: "Design a mobile app that lets people in a single dense urban neighborhood order groceries from a small number of local partner stores and get them delivered within the hour. Walk me through your approach from scratch."

1. Ask the clarifying questions you'd open with, and state the assumptions you'd make if the interviewer doesn't answer all of them.
2. Frame the core job-to-be-done — functional and emotional/social.
3. Define the MVP scope: the one primary flow you'd design in this session, and at least three things you'd explicitly declare out of scope.
4. Sketch the top-level information architecture (tabs/screens) and justify it.
5. Walk through the core flow's screens at wireframe level, naming at least one interaction-design principle behind a specific decision.
6. Write one empty-state message and one order-confirmation message.
7. Name one accessibility consideration specific to this app.
8. Propose one metric each for Task success, Adoption, and Retention.
9. Close with a one-sentence summary and the single highest-priority open risk.