SplitPay by Capital One

• 

  Use Cases Diagram

• 

  Prototype

Inspiration

We noticed that young adults and college students often struggle when sharing expenses. Whether it’s a dinner, a trip, or a group purchase, one person pays the full amount while others send transfers later, often with errors or delays. We wanted to create a seamless and secure solution that simplifies this process and integrates directly into the Capital One app.

What it does

SplitPay allows users to split a single payment across multiple Capital One accounts. Users can:

• Create a shared payment session
  
• Invite participants
  
• Set the total amount and optional extra charges (like tips)
  
• Divide the payment equally or customize contributions
  
• Confirm participation, after which Capital One processes one consolidated payment to the merchant
  

The result is a fast, secure, and transparent way to manage group payments without third-party apps or manual calculations.

How we built it

• Backend: Node.js + Express.js to manage sessions, invitations, and payment logic
  
• API: NessieIsReal API to simulate banking operations
  
• Frontend: React + Next.js + Material UI for a responsive and intuitive interface
  
• Flow: User creates session → sets amounts → participants confirm → consolidated payment sent
  

Challenges we ran into

• Simulating real banking operations without access to Capital One’s API
  
• Handling asynchronous updates when participants confirm payments
  
• Designing a responsive UI that works well on both mobile and desktop
  

Accomplishments that we're proud of

• Fully functional prototype demonstrating the entire payment flow
  
• Intuitive interface that simplifies collaborative payments
  
• Seamless integration of backend logic with frontend UI for real-time updates
  

What we learned

• Building a full-stack application with real-time interactions
  
• API integration and handling asynchronous data
  
• Designing flows that balance usability, security, and financial accuracy
  
• Working as a team to plan, implement, and test all components
  

What's next for SplitPay by Capital One

• Integrate with Capital One’s official API for real-world transactions
  
• Add notifications and reminders for pending payments
  
• Expand customization options for group payments (percentages, fixed amounts)
  
• Optimize the app for larger groups and more complex scenarios

Built With

• express.js
• javascript
• next.js
• node.js
• react
• typescript