Scan & Go: shoppers scan as they shop, cashiers close the sale.

1Problem

Scan & Go lets shoppers scan items on their phone while they shop, build a cart in the app, and show a QR code at the register, where a cashier completes the sale. It has to work for three groups at once: shoppers on mobile, frontline cashiers, and merchants running the pilot.

How might we let shoppers scan as they go, while cashiers and merchants stay confident about every sale?

2Process

• 2.1Start with shoppersPre-design research focuses on the shopper segment first, with a discovery interview guide now on its second version.
• 2.2Ask for stories, not yes or noEvery question opens with "tell me about", "walk me through" or "describe", so people share real incidents instead of opinions.
• 2.3Analyse in a fixed structureTranscripts are summarised in Notion AI with a reusable instruction set that keeps participants' exact words.
• 2.4Flag my own mistakesLeading questions or describing the product too early get called out in the analysis, so weak data is visible instead of hidden.

• Participant snapshot
• Verbatim quotes
• Stories and specific incidents
• Workarounds
• Trust and responsibility
• Physical constraints
• Concept reaction
• Contradicts assumptions
• Leading questions and data quality

3Design

Three design decisions are already fixed, before any screens, because they shape everything after.

• 3.1The cashier stays in the loopThis is not autonomous checkout. The cashier completes every sale, which keeps trust with staff and merchants.
• 3.2The QR code carries data, not moneyIt moves the cart to the register. It is not a payment token, so it can't be misused as one.
• 3.3Only call AI what is AIBarcode decoding is not AI. Overclaiming would cost the product its credibility.

4Status

Shopper interviews are underway. Concept screens come next, shaped by what shoppers say. Cashier and merchant research will follow.