DUOLABS
Work

Legacy payment app modernization

We handled feature development and maintenance, over a long period, for a payment app that processes card payments and other payment methods on mobile. Running it alongside another payment app built on the same foundation, we reflected this app's own requirements in its screens and payment flows. In a payment service, repeatedly confirming that existing payments still run correctly matters more than building fast. The work spans payment-state handling, camera document submission, multilingual messages, and app error management.

Launch
2020
Client
A payments company
Type
Payments
01 / 04

Payment results where success, failure, and pending are told apart at a glance

The core flow of the mobile payment app is payment request, authentication, result confirmation, and error-response handling. While keeping that flow stable, payment results were made to show three clearly separated states: success, failure, and pending. If a user mistakes pending for failure, or failure for success, they either pay again or walk away thinking the payment went through.

Payment results where success, failure, and pending are told apart at a glance
02 / 04

Camera document submission that holds together from permission to retry

The mobile payment app lets users photograph documents with the camera and submit them right in the app. This flow was built and maintained together with the exceptions that can occur in operation: camera permission requests, checking the captured result, upload failures, and retries. The rule was that wherever the flow stops, the user can tell what to do next.

Camera document submission that holds together from permission to retry
03 / 04

Payment and authentication error messages, reread in every language

The mobile payment app serves a broad range of users, so its screens and messages are offered in several languages. While applying the multilingual screens and text, error messages in the payment and authentication steps were singled out and checked. The test was less whether the translation was correct than whether a user reading the message knows at once what to do next.

Payment and authentication error messages, reread in every language
04 / 04

Separating shared errors from app-specific ones across two payment apps on one foundation

Crashes of the live mobile payment app were watched with an error-collection tool and fixed in priority order, starting with the spots that could grow into outages. This payment app was run alongside another payment app built on the same foundation, and problems common to both were handled separately from those found in only one. Payment services tolerate no defects, and the crash rate was kept very low throughout operation.

Separating shared errors from app-specific ones across two payment apps on one foundation

Highlights

01

Payment status display that keeps success, failure, and pending unmistakable

02

Camera document submission that covers permission, upload failure, and retry

03

Quality control that separated shared and app-specific errors across two payment apps on one foundation

Insights

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