.NET MAUI Cross-Platform App Development

Cross-Platform Mobile App Development with .NET MAUI

We develop cross-platform mobile applications on .NET MAUI — a single codebase for iOS, Android, and Windows. If your team already uses C# and ASP.NET Core, MAUI is a natural extension: the same patterns, same DI container, same NuGet. For enterprises where the mobile app is a frontend to a .NET backend, this is the optimal path in terms of team unification and code reuse.

.NET MAUI is the direct successor of Xamarin.Forms, but architecturally reworked. Instead of separate projects for each platform — a single csproj with conditional dependencies. This means one appsettings.json, one DI container (Microsoft.Extensions.DependencyInjection), one set of models. The transition is minimal: the patterns are the same, the tooling (latest Visual Studio / Rider) is the same.

Why .NET MAUI is faster than Xamarin.Forms?

MAUI uses Handlers instead of Renderers, reducing the view hierarchy by 2–3 levels and decreasing overhead by 30–50%. In practice, this means smoother scrolling and lower memory usage. Microsoft Learn: .NET MAUI Handlers.

Where Real Problems Arise

Hot Reload comes with caveats. XAML Hot Reload in the latest Visual Studio versions handles simple markup changes fine. But changes in C# code-behind or view models require a restart — .NET Hot Reload in MAUI is unreliable for complex hierarchies. UI iteration takes longer than in Flutter or React Native.

Binary size. A basic .NET MAUI APK without trimming is 30–50 MB. With PublishTrimmed=true and RuntimeIdentifier=android-arm64 we can compress it to 15–25 MB. However, trimming breaks Reflection, on which some NuGet packages rely. Every package must be checked for AOT/trimming compatibility.

NativeAOT on iOS is available with the latest .NET version. It gives better startup time and size, but requires complete abandonment of runtime Reflection. If the project uses System.Text.Json with source generators — fine. If Newtonsoft.Json — migration is mandatory.

How .NET MAUI handles offline mode?

Corporate app for field inspectors: offline work with forms and photos, synchronization when network appears. Stack: MAUI + EF Core SQLite + Polly for retry queue + Microsoft.Maui.Essentials for camera and GPS access. Platform-specific part: only file system access (different paths on iOS Documents vs Android GetExternalFilesDir). Compared to Xamarin.Forms, platform-specific code volume decreased by 40%. CI — Azure DevOps Pipelines with dotnet publish tasks per platform, signing via KeyVault.

Stack and Architecture

MVVM is the standard for MAUI. CommunityToolkit.Mvvm covers 90% of needs: [ObservableProperty], [RelayCommand], [NotifyCanExecuteChangedFor] via source generators. No manual INotifyPropertyChanged boilerplate.

Shell navigation (Shell) for standard cases; for complex navigation with object passing — NavigationPage or ReactiveUI.Maui. Prism.Maui — if the team is familiar with it from WPF/UWP.

Network layer — HttpClientFactory via DI, Refit for typed REST clients, Polly for retry/circuit breaker. gRPC client via Grpc.Net.Client works on iOS and Android without extra configuration starting from a certain .NET version.

Local DB — SQLite-net-pcl for simple cases, LiteDB for document-oriented storage. Entity Framework Core with SQLite provider works, but in trim scenarios requires EFCore.TrimmingSupport.

Push notifications — Plugin.Firebase.CloudMessaging for FCM; APNs on iOS configured via UNUserNotificationCenter in MauiProgram.cs.

Platform Integration

Access to native APIs — via Microsoft.Maui.Essentials: geolocation, accelerometer, Bluetooth, camera, biometrics (SecureStorage + Fingerprint). If access beyond Essentials is needed — DependencyService with platform-specific implementations or direct native code calls via #if ANDROID / #if IOS in partial classes.

Bindings to native SDKs: on Android — Java/Kotlin Binding Library via Binding Project; on iOS — ObjectiveC/Swift Binding via ApiDefinitions.cs. The procedure is labor-intensive but well-established.

Timelines

Cost is calculated individually after analyzing requirements and the client's existing .NET infrastructure. Contact us for a preliminary estimate.

What's Included in Development

• Source code in a repository (Git) with commit history;
• CI/CD pipeline (Azure DevOps / GitHub Actions) with signing and deployment;
• Architecture and API documentation;
• Setup of App Store Connect and Google Play Console (client accounts);
• Training the support team (2–3 sessions);
• Warranty for bug fixes within 30 days after delivery.

Order turnkey development — get a release-ready application.

What We Focus on During Audits

Three things we most often see in legacy MAUI projects: lack of trimming compatibility (app weighs 60+ MB), use of outdated Renderer from Xamarin.Forms instead of migrating to Handler, and synchronous DB operations on the UI thread via EF Core without async/await. The last one guarantees ANR on Android. We help migrate and optimize — write to us.

How to choose cross-platform development: Flutter, React Native, or KMM?

We often work with startups that need two apps—iOS and Android—with a budget for one team. Or corporations that want to release an internal tool in three months on both platforms. Cross-platform development solves a specific economic problem: one codebase instead of two. The question is not 'cross-platform or native'—it's 'which tool for which task.'

Each framework dictates its own stack and imposes limitations. An incorrect choice leads to rewriting the project in six months—we've seen it many times with clients who came to us after a failed first attempt. Therefore, before starting, we conduct an audit of technical requirements and team expertise. With 8+ years of cross-platform experience and 50+ delivered apps, we know the pitfalls firsthand.

The three main players now: Flutter, React Native, and Kotlin Multiplatform Mobile. They solve different problems and are poorly compared head-on. Below, we'll break down how to choose the best option for your project.

How do we choose the technology? 4 steps

1. Requirements analysis — list of native APIs, need for offline work, branded UI or standard.
2. Team assessment — expertise in Dart, JavaScript/Kotlin, availability of an iOS developer.
3. Proof-of-concept — implement a critical scenario on the chosen stack in 2–3 days.
4. Final decision — based on performance benchmarks and maintenance cost.

Case from our practice: a fintech startup needed an MVP on both platforms in 10 weeks. Their team had deep React experience, so we selected React Native. The app passed App Store and Google Play review on the first submission, and they launched on schedule. That choice saved 4 weeks compared to training for Flutter.

Comparison of Flutter and React Native: under the hood

Rendering model

Flutter renders UI independently via the Impeller engine (replaced Skia starting with version 3.10). The platform only provides a canvas—Flutter draws every pixel itself. This means:

• Pixel-perfect on all platforms. The same widget looks identical on iOS and Android—good for branded apps, bad if you need a 'native' look on each platform.
• No dependency on OS version. Material 3 in Flutter works the same on Android 8 and Android 14. System Android components are not involved.
• Platform channels for native code. Access to camera, Bluetooth, NFC—via MethodChannel or EventChannel. flutter_camera, flutter_blue_plus are wrappers over platform channels.

React Native uses native platform components. <View> on iOS is UIView. <Text> is UILabel. This means:

• Native look and feel without extra effort.
• New Architecture (Fabric + TurboModules) with JSI removed the JSON bridge between JS and native code. Synchronous calls work without serialization. This is critical for animations and gestures.
• React Native Reanimated 3 runs worklets on the UI thread—animations at 60/120 fps without blocking the JS thread.

Performance in practice

For most business apps, the performance difference between Flutter and React Native New Architecture is imperceptible. The difference appears in edge cases.

Flutter is slower when interacting with platform APIs via platform channels—each call is asynchronous, with data serialization overhead. google_maps_flutter renders the map via PlatformView—a native UIView/View embedded in the Flutter tree. Before Impeller, this caused performance issues (Hybrid Composition vs Virtual Display). With Impeller, Flutter renders UI 2–3x faster on low-end devices compared to Skia, and PlatformView performance improved by 40%.

React Native is slower in scenarios with heavy JS logic on the main thread. Parsing large JSON, complex computations—these block the JS thread and appear as UI freezes. Solution: Hermes (JS engine optimized for RN) + offloading computations to a native module or react-native-workers. With Hermes, cold start time is reduced by 30–40% compared to JavaScriptCore—that's 2x improvement on older devices.

Ecosystem and maturity

Dart is a barrier to entry for teams with a JS/TS background. It's possible to learn basic Dart in a week, but shifting your mindset to Flutter widgets and widget tree takes longer.

TypeScript in React Native is the de facto standard. A team with React experience becomes productive faster.

When to choose Flutter?

• Need a unified branded UI on all platforms (iOS, Android, Web, Desktop).
• Team is ready for Dart.
• Lots of custom animation and custom UI—Flutter is more predictable.
• The app is not tied to specific native APIs.

When to choose React Native?

• Team has React/TypeScript expertise.
• Need native look and feel.
• Heavy use of native components (Maps, Camera with native capabilities).
• Sharing code with React web via monorepo.

Kotlin Multiplatform Mobile: a different story

KMM solves not a UI problem, but the problem of business logic duplication. The concept: write business logic, networking, caching, validation once in Kotlin. iOS receives a .framework via Kotlin/Native, Android uses the library directly. UI on each platform is native.

// Shared Kotlin code — works on iOS and Android
class UserRepository(
    private val httpClient: HttpClient, // Ktor
    private val database: AppDatabase   // SQLDelight
) {
    suspend fun getUser(id: String): User {
        return database.userQueries.selectById(id).executeAsOneOrNull()
            ?: httpClient.get("$BASE_URL/users/$id").body<User>().also {
                database.userQueries.insert(it)
            }
    }
}

Ktor — HTTP client for KMM (works on iOS via Darwin engine, on Android via OkHttp). SQLDelight generates a typesafe Kotlin API for SQLite, works on both platforms.

Real limitations of KMM

Coroutines on iOS: suspend functions from shared code are called through automatically generated wrappers. SKIE (Swift/Kotlin Interface Enhancer) from Touchlab significantly improves the Swift interface: async/await instead of callbacks, AsyncStream for Flow. Without SKIE, working with coroutines from Swift is inconvenient.

Compose Multiplatform: JetBrains is developing Compose for iOS — UI in Compose works on iOS via Metal. This blurs the line with Flutter: one Compose code for both platforms. Status today: Beta, with early adopters in production (Touchlab, JetBrains own products), but stability is lower than Flutter.

Complexity of iOS integration: XCFramework from KMM module is added to an Xcode project. SPM integration exists and works. But iOS developers must understand the Kotlin API and memory management rules via Kotlin/Native (ARC + Kotlin GC work together, which is not always obvious).

When KMM is justified

The company already has mature iOS and Android teams that duplicate business logic. Switching everything to Flutter or React Native is too radical. KMM allows starting small: extract networking and models into shared code, keep UI native. Gradual migration without rewriting everything.

Typical mistakes in technology selection

Choosing Flutter "because it's a single codebase" for an app heavily reliant on native APIs (custom camera, BLE, background processing). Implementing these via platform channels adds complexity that eats up the development speed advantage.

React Native without understanding the JS thread. Heavy operations on the JS thread cause visible freezes. This is solvable, but requires understanding the architecture—otherwise the app will perform worse than native.

KMM without an iOS developer on the team. Shared Kotlin code requires an iOS engineer who integrates the framework into Xcode, writes SwiftUI on top of KMM APIs, and debugs Kotlin/Native crashes.

What is the development process and timeline?

A cross-platform project goes through the same stages as a native one: requirements audit → stack selection → design → development → testing on real devices of both platforms → publication in App Store and Google Play → support.

Testing on real devices is not optional. An emulator does not reproduce memory issues on budget Android phones and does not show differences in gesture behavior on iOS. We test 40+ scenarios on at least 5 real devices covering both OS versions.

Budget savings compared to two native teams can be up to 40–50%. The cost is calculated individually after analyzing the stack and requirements.

What's included in our work

• Technical audit and stack selection for your project.
• Architecture design (clean architecture, MVVM, BLoC/Redux).
• UI development according to design mockups for both platforms.
• Integration of native modules (camera, geolocation, push notifications).
• CI/CD setup (GitHub Actions, Codemagic).
• Testing on real devices (iOS/Android) — at least 40 scenarios.
• Preparation and publication in App Store and Google Play following guidelines (App Store Review, Google Play Policy).
• Technical support for 3 months after launch.
• Handover of source code, documentation, and access — all turnkey.

We'll evaluate your project in one day—get a consultation on stack selection. Order turnkey development and receive a cross-platform app within the agreed timeline, backed by our experience and guaranteed milestones.