hardDesignScenarioMidSeniorStaff
A driver spends part of the day with no mobile signal. How do you design the app so the round still works?
5 min readUpdated 2026-08-15
Answer
Short answer
Treat the device as a first-class writer rather than a cache: it generates its own identifiers, records two timestamps per event, and queues durably until the network returns.
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Likely follow-ups
- The driver's phone dies with forty events queued. What have you lost?
- Two contradictory delivery outcomes arrive for one parcel. Which wins?
- How do you handle a proof-of-delivery photo on a bad connection?
- What does the customer-facing tracking page show while events are queued?
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