Case note · 11 weeks
A grocery checkout that looked healthy until the grid was drawn
A Chiang Rai retailer joined In-house Residency after a redesign that raised “add to cart” and quietly flattened completed orders. Their funnel treated OTP, PromptPay confirmation, and the success screen as one “payment step.”
During week two we rebuilt the queue as nine cells. Cell six — a “confirm amount” screen that appeared only on some banks — held people for a median of 41 seconds, then returned them to the cart with a toast that looked like a success. The heatmap for that screen was almost empty because few sessions reached it, so it had never been a slide.
The team did not redesign the visual. They removed the extra confirm for wallets that already showed the amount, and renamed the toast. Completed orders recovered 11 points over six weeks. The residency write-up named the limitation clearly: we never saw offline shoppers sharing a phone, so the grid is still incomplete for that group.
Shared with permission. Figures are the retailer’s internal numbers, not a Systemqueuegrid claim about every grocery app.