Kotlin is primarily used to develop Android applications. According to Google, 60% of professional Android developers use Kotlin, and around 95% of the 1,000 top Android applications contain at least some Kotlin code. Google also estimates that around 70% of the apps on the Play Store are built with Kotlin. Kotlin is extensively used for Android development, and still seems to be on an upward trajectory.

Kotlin is seeing increased use for server-side development and offers full compatibility with existing Java-based technology stacks and Java-based frameworks. Kotlin’s expressive and concise syntax helps to keep coding efficient and maintainable.

Kotlin is extensively supported by Java frameworks such as Spring, with Spring-specific tooling available, extensive supporting documentation, and respectable IDE support. Since Kotlin supports concurrent programming, scalability is another reason why it’s seeing increased use for server-side development. Kotlin’s Coroutines and optimized hardware usage play key roles for server-side scalability.

Kotlin-supported frameworks for server-side development include:

Kotlin allows for multi-platform programming using the same codebase while leveraging some of the benefits of native code. Multi-platform programming helps to save time as less code is required and helps streamline maintenance and cross-platform implementations. Kotlin supports multi-platform programming in 3 main ways:

Kotlin is a concise programming language thanks to modern features including type inference, infix functions, and data classes. Kotlin reduces time spent on boilerplate code as it is an object-oriented programming language that can use functional programming. This frees up the developers’ time to work more on functionality and the application’s business logic.

Kotlin is also an expressive and lightweight language, letting developers achieve the same tasks as other languages such as Java, with fewer lines of code. The drawback of Kotlin’s expressive and concise syntax is that it can be a little more complex at the beginning for developers that are used to working with Java.

Kotlin is considered a very safe programming language with features that help developers avoid and greatly reduce errors such as NullPointExceptions. In Kotlin, semicolons are optional, named parameters keep code readable (and therefore enhance maintainability), optionals (“?”) allow passing null values, and support passing code as functions and Lambda.

Achieving Kotlin’s level of safety in Java required a lot of extra code and work on the developer’s part. When Kotlin’s safety features are combined with its simple, clear, and concise syntax, maintaining complex codebases and working with Kotlin at large scales is eased.

Android Jetpack is a collection of libraries that you can import into your Kotlin application to help developers follow the best modern practices, reduce memory leaks and thus get fewer crashes, and allow backward compatibility with older versions of Android.

Jetpack helps reduce fragmentation in Kotlin applications when using complex libraries across several different Android devices and Android versions. Jetpack’s libraries also guide developers into writing good code that works across different Android devices and versions.

Using Jetpack with Kotlin (and Android KTX), the amount of time spent writing boilerplate code is reduced as there are libraries to handle operations such as lifecycle management, background processes, navigation, etc., giving developers more time to focus on the code’s functionality and business logic.

Jetpack Compose is Android’s recommended toolkit for building native UI, making it quicker and easier to develop UIs for Android applications with less code and powerful Kotlin APIs. The main issue with Jetpack Compose is its lack of maturity, being a relatively new toolkit. Many developers prefer to use more established toolkits for building UI such as XML – though this may change as Compose reaches maturity.

Using Kotlin’s Coroutines, developers can build applications that support concurrency/asynchronous/non-blocking applications with Kotlin. For example, heavy computational work can be handled without blocking updating the UI.

Kotlin Coroutines simplify the asynchronously executed code and manages computational tasks that would typically block the main thread, thus preventing the app from becoming unresponsive.

Kotlin’s coroutines are lightweight and several coroutines can run on a single thread without blocking the thread running the coroutine as Kotlin supports suspension.

Android Jetpack supports Kotlin Coroutines, with several popular Jetpack libraries coming with extensions that provide comprehensive coroutine support – with some even supporting structured concurrency (for fewer memory leaks).

Android Studio is the official IDE (Integrated Development Environment) for building Android applications. Android Studio offers an intelligent code editor with a host of autocomplete and assistive features to make coding faster, more intuitive, and better organized.

Developers can build multiple builds for various Android versions and devices from a single project through technologies such as Gradle, saving developers’ time and getting applications to production-ready more efficiently.

Android Studio also provides a suite of features and tools that make it easier to emulate various devices, fine-tune code with live feedback, and even access newer UI features such as Jetpack Compose.

Android KTX is a set of extensions for Kotlin that come with Android Jetpack (and some other popular Android libraries). Android KTX helps to make writing code in Kotlin more natural, idiomatic, and concise. It also includes an API layer for Kotlin to the Android framework and various supporting libraries.