What is the architectural difference between MVVM and MVI in Android?

Short answer

MVVM usually relies on several independent state streams, while MVI imposes a single immutable state with a strict flow of intents and side effects.

Explanation

In traditional MVVM you may find isLoading, users, and errorMessage as separate StateFlows, which can sometimes cause inconsistent states. In MVI (Model-View-Intent) the screen is represented as one comprehensive state through a data class or sealed interface, and user wishes are received as intents, while individual quick events (such as navigation or showing a Snackbar) are expressed as single-event side effects.

Code example

// MVI State
data class ProfileState(
    val isLoading: Boolean = false,
    val profile: Profile? = null,
    val error: String? = null
)

// MVI Intent
sealed interface ProfileIntent {
    data object Load : ProfileIntent
    data class UpdateBio(val newBio: String) : ProfileIntent
}

Common mistakes

• Resending the same one-off event such as showing a Toast every time the UI is recomposed in MVI because it was not isolated from the state.

Follow-up questions

• What is the unidirectional data flow (UDF) pattern?

Sources

• Android Developers — Architecture guide / UI events