Making Substitution Approval Simple

Decisions under a Deadline

Client

Unnamed Grocery Delivery App

Role

UI/UX Designer

Duration

1 month (2025)

Challenge

When a personal shopper finds an item out of stock, the customer has about five minutes to answer and is usually at work, in a meeting, or driving. Most delivery apps treat this as a preference question. A vague push notification, a substitute picker buried three screens deep, and a price change that doesn't surface until checkout.

The item quietly disappears, the customer finds out at the door, and a refund lands with no explanation attached to it.

So the design problem isn't picking a replacement product. It's making a timed decision answerable by someone who isn't looking at their phone.

Approach

I moved the decision out of the app and into the notification. The push names both products, states the price difference, and gives a clock time instead of a ticking countdown, so it can be answered from a lock screen in one tap. The in-app screen became the fallback for people who want to look closer, not the primary interface.

I stacked the original item above the replacement instead of placing them side by side. Two columns look tidier in a screenshot, but at phone width they force the eye to compare two 44-pixel labels. Stacked with a downward arrow, one item visibly replaces the other, and the layout does the comparison instead of the reader.

I put the price difference in its own row directly above the primary button. Unexplained charges are the most common complaint in delivery app reviews, and a plus-fifty-cents stated before the tap turns a possible refund dispute into a two-second decision.

I created a horizontal timeline widget at the bottom of the dashboard. Divided by week, it shows completed results, active games, and upcoming fixtures to showcase league activity and prove value to potential sponsors.

I designed the ignored path first. Four of the six states in the sheet involve the customer never responding, because that's the majority case for anything triggered by a notification. Expiry produces an automatic refund plus a plain-language notice, so silence resolves cleanly instead of becoming a surprise at the door.

Solution

A notification-first substitution flow that reduces the common six-tap, app-launch path to a single lock-screen tap, states the cost of the swap before the customer commits to it, keeps an undo window open until checkout, and resolves automatically.

Results & Tradeoffs

Tradeoff: A single suggested replacement is narrower than a dropdown. That trade is wrong for a customer with strong brand preferences, which is why "other options" sits directly beneath the approve button rather than behind a menu.

Tradeoff: Fewer taps can mean more accidental approvals.The tap count is a property of the design, not evidence that it works. The undo window exists specifically to absorb that risk, and undo rate is the counter-metric I'd watch.

Average Support contacts per 100 lowered by ~15% mentioning a wrong, missing, or unexpected item.

Post-delivery refund requests citing price fell by ~20%.