Series 1 of 2 — Part 4 of 5

Building a Flutter Shopping App — Part 4: The Big Refactor — Migrating to MVVM

Series: Building a Flutter Shopping App — From Zero to Architecture

By Part 3 the app was working — auth, Firestore, notifications, all functional. But the codebase was becoming uncomfortable to work in. Adding a feature meant touching multiple files in ways that felt wrong. The providers knew too much. Business logic was everywhere.

My internship mentor pointed me toward MVVM. I read about it, looked at the codebase with fresh eyes, and understood the problem for the first time: there was no separation between where data came from, how it was processed, and how it was displayed.

So I refactored the entire app to MVVM.

What MVVM means in Flutter with Riverpod

Model : Pure data classes. No Flutter, no Riverpod, no Firebase — just data.

Repository : Where data comes from. A ProductRepository talks to Firestore. A CartRepository reads from local storage.…