Clean Architecture vs. Pragmatic MVVM: Benefits and Trade-offs in Dual-Platform Development

Introduction

In native cross-platform development (Android with Kotlin and iOS with Swift), choosing an architecture is a strategic decision that directly impacts productivity, maintainability, and consistency. Clean Architecture (Layered) and Pragmatic MVVM (Lean) are the two most prominent contenders. Both are powerful, and both can be applied effectively to either platform.

In my recent projects, I experimented with Clean Architecture on Android and Pragmatic MVVM on iOS to compare their real-world performance. (Note: This was a controlled experiment; one could easily reverse them—applying Clean Arch to iOS and Pragmatic MVVM to Android). The results highlighted that while each brings unique value, they also demand non-trivial trade-offs that compound quickly when maintaining two native codebases.

This article provides an objective analysis of the benefits and costs of each approach and offers a strategy for achieving Conceptual Parity without unnecessary complexity.

Why the Divergence in Approach?

The choice between Clean Architecture and Pragmatic MVVM isn't dictated by the OS, but rather by project context, team philosophy, and specific priorities:

• Clean Architecture emphasizes separation of concerns, dependency inversion, and high testability. It is the go-to for codebases that need to be highly scalable and independently testable.
• Pragmatic MVVM focuses on simplicity, minimal boilerplate, and leveraging the native reactive features of modern frameworks (SwiftUI/Compose). it is ideal for rapid iteration and high development velocity.

Whether you choose one or the other depends on the maturity and complexity of the feature—not on whether the file ends in .kt or .swift.

Benefits of Each Approach

1. Clean Architecture (Layered, with UseCase/Interactor)

2. Pragmatic MVVM (Lean, logic primarily in the ViewModel)

The Price to Pay

In cross-platform native development, the biggest "cost" is often inconsistency: maintaining two different approaches makes it harder to sync logic and increases the risk of subtle bugs.

The Solution: Conceptual Parity

You don't need to force a single rigid structure on both platforms. Instead, focus on mirroring core concepts to maintain high consistency.

1. Data Layer Abstraction

Ensure the data-fetching strategy remains identical.

• Android: Repository Interface + Impl.
• iOS: Protocol + Concrete Class/Struct.

2. Unified Business Logic Placement

To maintain parity, prioritize extracting business logic from the ViewModel on both sides:

• Use UseCases in Android and Interactors (or similar) in iOS.
• This keeps rules in a dedicated, testable, mirrorable location.

Golden Rule: Extract by default if there are significant business rules. For truly simple "fetch and show" cases, keep in ViewModel—but apply the same rule on both platforms to avoid inconsistency.

3. The ViewModel as the Orchestrator

Both sides should treat the ViewModel as a state machine:

• Use UiState (Sealed Classes / Enums).
• Mirror Events and Side-effects.

4. Documenting the "Golden Path"

Maintain a docs/architecture-guidelines.md that defines:

• "Logic belongs in UseCases/Interactors for testability."
• "Data access must always go through a Repository/Service abstraction."
• "Error handling, loading states, and retry logic must be mirrored exactly."

Practical Code Parity: Login Flow

Android (Clean Arch - UseCase)

// domain/usecases/LoginUseCase.kt
class LoginUseCase @Inject constructor(private val repo: AuthRepository) {
    suspend operator fun invoke(email: String, password: String): Result<User> { ... }
}

// presentation/viewmodel/LoginViewModel.kt
class LoginViewModel @Inject constructor(private val loginUseCase: LoginUseCase) : ViewModel() {
    fun login(email: String, password: String) { /* Logic execution */ }
}

iOS (Matching with Interactor)

// domain/interactors/LoginInteractor.swift
class LoginInteractor {
    private let authService: AuthService
    init(authService: AuthService) { self.authService = authService }

    func login(email: String, password: String) async throws -> User { ... }
}

// presentation/viewmodel/LoginViewModel.swift
@MainActor
class LoginViewModel: ObservableObject {
    @Published var uiState: LoginUiState = .idle
    private let interactor: LoginInteractor

    init(interactor: LoginInteractor) { self.interactor = interactor }

    func login(email: String, password: String) async { /* Logic execution */ }
}

Final Thoughts

Clean Architecture and Pragmatic MVVM are both excellent choices—neither is objectively superior. In native cross-platform development, the real value lies in Balance.

By embracing Conceptual Parity and maintaining a shared "Golden Path," you allow each platform to play to its strengths while ensuring the codebase remains synchronized, testable, and easy to maintain.