Design Splitwise

Let's make an object-oriented design for Splitwise, a system for sharing expenses between friends.

Four people go on a trip. One pays for the hotel, another for dinner, a third for the taxi. At the end nobody remembers who owes what. Splitwise is the app that keeps that record, and the interesting part of the design is not the screens. It is deciding where the money arithmetic lives, so that every number in the system still adds up after every action.

System Requirements

We will focus on the following set of requirements while designing Splitwise:

1