One of the biggest challenges was that our problem wasn’t purely technical — it was emotional and social. Most expense apps deal with numbers, but we were trying to design something that reduces awkwardness, resentment, and stress between roommates. Turning human emotions into a system feature was not easy.

Designing the fairness logic was also challenging. We wanted a system that suggests who should pay next without feeling random or unfair. Balancing simplicity and fairness required a lot of thinking about user trust, not just calculations.

Another challenge was keeping the app simple yet intelligent. We didn’t want students to feel overwhelmed by complex data, so we had to hide the smart logic behind a clean, friendly interface.

As first-year students, building a multi-page app flow instead of a single demo screen was new to us. We had to quickly learn how to connect pages, store user data, and make the app feel like a real system.

Finally, designing polite reminders instead of aggressive “you owe money” messages was tricky — because we had to think from a psychological perspective, not just a technical one.