DUOLABS
Work

Mobile payment app upgrades and operations

We improved and ran the payment features of a mobile payment service operated by a card issuer. People pay with it every day, so a single defect is immediately a money problem. As payment methods were added and screens changed, the priority was keeping existing payment flows steady. The work spans the whole service where app, web, and server meet: the payment screen, registering other issuers' cards, billing history, and release automation.

Launch
2024
Client
A Korean card issuer
Type
Payments
01 / 04

Pick a card, account, or points and pay with one barcode

The in-store payment screen lets a customer pick one of their registered credit or debit cards, bank accounts, points, or gift vouchers and pay with a barcode or QR code. It is used at the checkout counter, so the few seconds between opening the app and seeing the code are felt directly. The rule for this screen was that adding payment methods must not lengthen the step of choosing one.

Pick a card, account, or points and pay with one barcode
02 / 04

Payment-method registration that puts other issuers' cards on the same list

For the open payment scheme in which card issuers accept each other's cards, we developed the flow for registering other issuers' credit and debit cards. Under payment-method registration, the customer picks an issuer and adds a card, and it lands on the same list as the issuer's own cards to be chosen on the payment screen. Because each issuer has its own rules but they share one list, every release separately checked that payments with the issuer's own cards were unaffected.

Payment-method registration that puts other issuers' cards on the same list
03 / 04

A billing screen that runs from the upcoming amount to early payment

The billing screen shows this month's upcoming payment amount and each card's transaction history, and leads into early payment before the due date. A wrong amount on this screen turns straight into a call to customer service, so the screen shows the amount exactly as the server sends it, without recalculating or rounding it.

A billing screen that runs from the upcoming amount to early payment
04 / 04

Release automation that removed the manual work from every release

Every release of a financial app comes with a build, signing, store review submission, and a version record. When people walk through those steps by hand, a step gets skipped or a build goes out with the wrong settings. We automated the repeated release procedure so that whoever ships it, the same steps run in the same order with the same result.

Release automation that removed the manual work from every release

Highlights

01

Barcode and QR payments that pick a card, account, or points on one screen

02

Payment-method management that also takes other issuers' cards

03

Release automation that cut the manual steps and room for error in every release

Insights

Read the blog