Kotlin Development for Android and Shared Business Logic
Kotlin engineering across Android apps, Kotlin Multiplatform modules that share logic with iOS, and the migration of Java codebases onto Kotlin without stopping feature work.
What is Kotlin used for and what is Kotlin Multiplatform?
Kotlin is the primary language for Android development and also runs on the JVM for server-side work. Kotlin Multiplatform, or KMP, lets you write business logic, networking and data layers once and share them across Android, iOS, desktop and web, while each platform keeps its own native user interface. Anviam builds Android apps in Kotlin with Jetpack Compose, uses KMP where two or more platforms genuinely share complex logic, and migrates existing Java Android codebases to Kotlin incrementally.
- Primary use
- Android apps and shared modules
- UI toolkit
- Jetpack Compose, Compose Multiplatform
- KMP sharing
- Logic, networking, persistence — not UI
- Java migration
- Incremental, file by file
- Server-side
- Ktor and Spring Boot with Kotlin
- Engagement
- Project build or embedded engineers
Share the Logic, Not the Interface
Kotlin Multiplatform is frequently mis-sold as a way to build one app for two platforms. It is not, and it is better than that framing suggests. KMP shares the layers where duplication actually causes bugs — validation rules, pricing calculations, sync and conflict resolution, API clients, offline caching — while each platform keeps a fully native UI. You avoid the two-implementations-drifting-apart problem without adopting a cross-platform look and feel.
That makes it a good fit when logic is genuinely complex and shared, and a poor fit when the app is mostly screens over a simple API. In the latter case KMP's build complexity buys you little, and either two native apps or a Flutter build will serve you better. We assess which of those three you are actually in before recommending it, because the wrong choice here is expensive to unwind.
Kotlin Development Services
Android Apps in Kotlin
Native Android development with Jetpack Compose, coroutines and a clean architecture that survives feature growth.
Kotlin Multiplatform Modules
Shared logic, networking and persistence consumed by native Android and iOS applications.
Java to Kotlin Migration
Incremental conversion of existing Android codebases, file by file, with no feature freeze required.
Kotlin Server-Side Services
Backend services in Ktor or Spring Boot with Kotlin, often sharing models with the mobile client.
Compose Multiplatform
Shared Compose interfaces across Android and desktop where a common UI is genuinely appropriate.
Testing & Architecture Cleanup
Introducing testable architecture and coroutine-aware tests into codebases that lack both.
The Kotlin Ecosystem We Work In
Where Kotlin and KMP Make Sense
Complex Business Rules
Pricing, eligibility or regulatory logic that must behave identically on every platform.
Offline Sync Engines
Conflict resolution and sync logic too intricate to safely implement twice.
Fintech & Insurance Apps
Calculation-heavy products where a platform discrepancy is a compliance problem, not a cosmetic one.
Ageing Java Android Apps
Long-lived Android codebases in Java that need modernising without pausing delivery.
Multi-App Portfolios
Several apps from one organisation duplicating the same domain logic in each.
Shared Client and Server Models
Teams wanting one definition of their domain model across backend and mobile.
How a Kotlin Engagement Runs
Fit Assessment
An honest call on native, KMP or a cross-platform framework, based on how much logic is genuinely shared.
Module Boundaries
Deciding what belongs in shared code and what stays platform-specific, before implementation.
Build & Integrate
Shared modules built with tests, then consumed by the native apps behind clean interfaces.
Migration in Slices
For existing codebases, conversion in shippable increments alongside continuing feature work.
Enable Your Team
Documentation, patterns and pairing so your engineers can extend the shared code themselves.
Common Questions About Kotlin Development
Should we use Kotlin Multiplatform or Flutter?
They solve different problems. KMP shares logic and keeps native interfaces on each platform, which suits apps where the UI must feel genuinely native and the complexity lives in business rules. Flutter shares the entire application including the interface, which suits apps where a consistent custom look is acceptable and speed to two platforms matters most. If your app is mostly forms and lists over an API, Flutter is usually faster to ship; if it is calculation-heavy with demanding native UX, KMP fits better.
Is Kotlin Multiplatform production-ready?
For shared logic, yes — it is stable and used in production by large organisations, and the iOS interoperability story has improved considerably. The caveats are practical rather than existential: build tooling is more complex than a single-platform project, some libraries still lack multiplatform support, and your iOS developers need to be comfortable consuming a Kotlin-produced framework. Compose Multiplatform for shared UI is more mature on Android and desktop than on iOS.
How do we migrate an existing Java Android app to Kotlin?
Incrementally, because Kotlin and Java interoperate within the same module. The usual approach is to write all new code in Kotlin, convert files when you are already changing them, and prioritise the classes that change most often. Android Studio's automatic converter handles the mechanical part but produces non-idiomatic Kotlin, so converted files need a review pass to use null safety, data classes and coroutines properly rather than transliterated Java.
Do you use coroutines or RxJava?
Coroutines and Flow for new work; they are the current standard, integrate directly with Jetpack libraries and Compose, and produce considerably more readable asynchronous code. We still work in RxJava codebases and can migrate them incrementally, usually at module boundaries, since the two can coexist through interop adapters while the conversion proceeds.
Can Kotlin be used on the server side too?
Yes, and it is a good option when the same team owns mobile and backend. Ktor is Kotlin-native and lightweight; Spring Boot with Kotlin is the pragmatic choice for enterprise environments already invested in Spring. The real benefit is sharing domain models and validation between server and Android client, which removes a class of drift bugs where the two disagree about what is valid.
Can you provide Kotlin developers for our team?
Yes. Kotlin and Android engineers can be engaged as an embedded extension of your team, working in your repository and sprint process on a rolling monthly basis, typically onboarding within five to ten business days with four or more hours of daily overlap with your working hours.