PaymentApp

Inspiration

We realized that managing personal finances and banking transactions is often fragmented, complex, and lacking in transparency. With the growing trend of Open Banking, we wanted to create a mobile application that helps users securely connect multiple bank accounts, easily track income and expenses, and make transactions quickly – all in a single platform.

What it does

Connect multiple bank accounts via Open Banking API. View balances, transaction history and spending analysis from all accounts. Quickly transfer money between linked accounts. Set up transaction notifications, spending limits and spending categories. Secure login with biometrics (fingerprint/face). Support QR code payment (VietQR).

How we built it

Frontend: Use React Native and Expo to develop cross-platform applications (iOS/Android). Backend: Use Node.js (NestJS) combined with MongoDB to process user data and communicate with banking APIs. Open Banking Integration: Connect to banking APIs according to PSD2/OpenAPI standards or integrate through intermediary services such as Salt Edge, Tink,... Security: Use end-to-end data encryption, OAuth2 authentication and device biometrics. Push Notification: Integrate Firebase Cloud Messaging (FCM) to send real-time notifications.

Challenges we ran into

Integrating with multiple banks’ APIs requires understanding each system and handling differences in data standards. Ensure absolute security in storing and processing personal financial data. The user interface must be intuitive and UX optimized for both general and financial-savvy users. Optimize application performance when processing large amounts of transaction data.

Accomplishments that we're proud of

Successfully integrate multiple banks in just one application. User-friendly, beautiful and easy-to-use interface design. Ensure fast response speed, even with multiple accounts and large transactions. Biometric security is deployed stably on both Android and iOS.

What we learned

Practical knowledge of Open Banking standards and how financial APIs work. Deep understanding of mobile security, especially handling sensitive data such as banking information. Experience working in a team with a clear frontend/backend division. Understand how to build a fintech mobile application from design to implementation.

What's next for PaymentApp

Expand support for more domestic and international banks. Integrate investment features, automatic savings, and bill reminders. Apply AI to suggest smart spending and financial forecasts. Cooperate with fintech partners to provide more convenient financial services to users.

Built With

• react-native