How can Kotlin multiplatform improve your mobile app development?

In the past two years, I’ve worked extensively with Kotlin Multiplatform, both in greenfield and brownfield projects. Its notable strength lies in its versatility as an SDK, effortlessly integrating into or removing from any project. Start with small use cases like analytics, testing its viability, and gradually expand code sharing. In greenfield projects, it facilitates rapid prototyping and scaling for substantial modules. Initially designed for business logic sharing, Kotlin Multiplatform now embraces Compose Multiplatform, allowing for uniform UIs. Compose UI seamlessly functions within Swift UI, UIKit, and even Swing and JavaFX. This significantly enhances the benefits of Kotlin Multiplatform

With these many alternatives in the cross-platform domain. The main power of Kotlin Multiplatform comes from using it in existing projects. This is because you can choose how much of your code you can share. Choose your util functions Then move to your database operations using SQL delight Then move to your code using network logic Then MVVM pattern FInally the UI. This i feel is the biggest advantage. Also with it's increasing no of targets all kotlin codebases are not that far off

Imagine a pizza chef who has perfected a universal dough recipe. This dough—much like shared Kotlin code—forms the base of pizzas in two different eateries: ? An Italian-style restaurant, which adds classic toppings (iOS-specific features) ? An Indian diner adds local favorites (Android-specific elements) Using Kotlin Multiplatform Mobile (KMM), developers: ? Craft this foundational “dough” (core app logic) once in Kotlin. ? Use it across both platforms. ? Customize with unique “toppings” (user interface and platform-specific features) for each. This approach boosts efficiency by using a single recipe, ensures consistency with the same base across all pizzas, and allows for customization to cater to local tastes.

A few points I would like to add - - Kotlin multiplatform is still in beta. - Kotlin multiplatform compiles (transpiles) your kotlin code to native, javascript etc.

Kotlin Multiplatform offers a compelling option for mobile developers seeking efficiency and broader reach. By sharing core logic, data models, and business rules across Android and iOS, it dramatically reduces code duplication, saving valuable development time and resources. Yet, it avoids the performance pitfalls of hybrid frameworks by utilizing native libraries on each platform, ensuring a buttery-smooth user experience. This allows for faster development cycles with simultaneous updates for both platforms, keeping your users consistently engaged. Moreover, it deepens your Kotlin expertise while expanding your mobile skillset, making you a more marketable and versatile developer. For those looking to write once and conquer twice, go KMM

It's a great tool to empower you to decide how much code base want to share between platforms. It's very depends on each product.

The Kotlin Multiplatform technology is designed to simplify the development of cross-platform projects. It reduces time spent writing and maintaining the same code for different platforms while retaining the flexibility and benefits of native programming

Main benifits of KMP is for Android Developers is Kotlin language and Jetpack Compose. For other developers like ios developers, they knows swift, so syntax wise kotlin is also similar. Native performance for all platforms using Kotlin multiplatform. Other cross platform doesn't provide native performance. Jetpack compose supports UI development for all platforms and your business logic also common. So it's benifits to developers as well as users. They don't compromise in the app performance. Many companies switch to KMP for production apps.

Kotlin multiplatform enhances mobile app development by enabling code sharing across platforms, reducing duplication and enhancing consistency. This approach streamlines development, accelerates iteration cycles, and facilitates easier maintenance, ultimately leading to faster time-to-market and cost-effectiveness.

To begin with Kotlin multiplatform: Install Kotlin & KMM Plugin: Install the latest Kotlin version and the KMM plugin for Android Studio or IntelliJ IDEA. Create/Convert Project: Create a new KMM project or convert an existing Android project to KMM. Add iOS Target: If targeting iOS, configure Xcode settings for the iOS module. Write Common Code: Develop shared code in the shared module for business logic and common functionality. Platform-Specific Code: Create Android and iOS modules for platform-specific code. Test & Debug: Use KMM plugin tools to test and debug your app on both platforms. This concise guide helps you kickstart Kotlin multiplatform development for mobile apps.

To begin your journey with Kotlin Multiplatform, you absolutely require the KMM plugin for Android Studio. Additionally, ensure the setup of an iOS simulator, enabling comprehensive testing across both platforms. With the environment in place, it's time to dive into coding. Organize the folder structure, distinguishing between shared, common, and platform-specific components. As you engage with Kotlin Multiplatform, persist in learning about optimal practices, libraries, and tools that amplify your development process. Given Kotlin Multiplatform's ongoing evolution, maintaining up-to-date knowledge remains vital.

Starting with Kotlin Multiplatform: Install Kotlin: Get Kotlin on your machine. Set up IDE: Use IntelliJ IDEA or Android Studio with Kotlin plugin. Create Project: Build a Kotlin Multiplatform Project with shared and platform-specific modules. Write Shared Code: Develop common code in the shared module. Add Platform Modules: Create modules for each target platform. Configure Dependencies: Use expect/actual for shared and platform-specific APIs. Build and Test: Test on each platform. Iterate: Keep developing and adjusting for platform specifics. Publish: Share your project via a repository. Learn: Explore Kotlin Multiplatform docs and tutorials for insights.

Some points I like to add - - Keep things common as much as possible - Write Unit test from beginning - Use DI from beginning - Prefer common Kotlin libraries

Focus on sharing business logic, data models, and utility functions across platforms. Keep platform-specific code to a minimum to maximize code reusability. Choose a clear architectural pattern that aligns with Kotlin Multiplatform's capabilities. Popular choices include MVVM, Clean Architecture, or MVI. Maintain a clear separation between shared code and platform-specific code. This enhances modularity and makes it easier to manage code changes. Implement platform-specific UI components to ensure a native user experience. Consider using Kotlin Multiplatform libraries for UI components, such as Jetpack Compose for Android and SwiftUI for iOS.

Based on my analysis of the most recent trends, some best practices for Kotlin multiplatform include defining clear boundaries between shared and platform-specific code, using common APIs to ensure consistency across platforms, and leveraging platform-specific features when necessary. Additionally, it's important to have a solid testing strategy in place to ensure that your code works seamlessly across all platforms.

I firmly believe that Adoption of certain Kotlin Multiplatform (KMP) practices has revolutionized our software development approach. These practices include strategic planning, the expect/actual mechanism, the Kotlin Gradle plugin, embracing continuous integration (CI), maintaining a balance with platform-specific libraries, rigorous testing across platforms, adhering to clean code principles, recognizing documentation as our lifeline, maintaining version control for harmonious collaboration, implementing a unified error-handling approach, prioritizing performance optimization, staying actively engaged with the community, mastering the art of abstraction, and adeptly adapting to platform variability.

Always start with the domain-layer or business logic to starting of. You can do more with common/shared code on the data-layer or presentation-layer later on. Just ensure that in the domain-layer is pure koltin code, and pay attention to as well to a jvm code introduced in domain-layer (common code), like java.time is not available for non-jvm environments, so need to add a dependency that loosely coupled with JVM, and target to KMP instead. Imho, sharing the domain-layer is already good enough. Even though debatable for the data-layer to be shareable across multiple OS. As data-layer means we need to check 3rd party libs that support every OS we target, and in this state still early and only few of them exist

Although KMP aims at code sharing across platforms, there are numerous cases where platform-specific code must be included. That can be both OS-dependent features and UI. In some application, the amount of sharing code might be much smaller than platform-specific code.

As a mobile engineer, a major limitation of Kotlin Multiplatform Mobile (KMM) is that it converts Kotlin code to Objective-C for iOS compatibility, not directly to Swift. This requires iOS developers to handle Objective-C bridging, which is more cumbersome and less intuitive than using Swift. This extra layer can complicate development and lead to issues when integrating with the latest iOS features and APIs, which are optimized for Swift. Moreover, despite superficial similarities between Kotlin and Swift, they are fundamentally different languages. If the Kotlin code shared via KMM is poorly crafted, it can be challenging for iOS developers working in Swift to manage and debug it effectively.

Handling platform-specific intricacies, such as UI differences or platform-specific APIs, can be challenging. Maintaining a consistent user experience across platforms can be demanding. On the other hand, while Kotlin Multiplatform is gaining popularity, not all third-party libraries are compatible with it. You might need to implement custom solutions or find alternatives. Finally, despite efforts to share code, there might still be instances where platform-specific code is duplicated, reducing the benefits of code reusability.

There were more challenges years ago with the initial releases of Kotlin multiplatform, for example, because of the memory model of iOS targets. Fortunately, it was resolved. Nowadays, challenges are common in any other cross-platform solution when specific native implementations are required, for example running and managing background services that work differently on different platforms, requiring native languages to be used. This is why a good architectural design is so important to support different implementations only when needed and reduce the effort and bugs.

It is still a very "crude" tool to create products for production. it may improve in the future, but there are many things that do not have good documentation or change very quickly Be careful with this choice.

One thing that's a benefit is unified testing. Shared logic can be tested once, ensuring consistent behavior across platforms. While UI or platform-specific tests will still be separate, a large chunk of logic tests can be unified.

I don't believe that KMM would replace other hybrid platforms because still most of the developers and organizations are not moving to it due to their currently running apps. Secondly, after launching CMP, the KMM is also coming in the same bench that writes a shared UI for every platform, it defines that now native UI wording is gone. Still, need clarity on it?? It concludes that the community still needs time to experience KMM and its issues. Also, Google to work on launching currently available Android libraries to support KMM.

Programmers are drawn to Kotlin Multiplatform because of its thriving community. This community provides a platform for sharing ideas, offering assistance, and ensuring that developers are not left isolated in their projects.