Kotlin is an open-source programming language created by JetBrains. It is open-source and statically typed, and it is used by major tech companies, including Google, Amazon, Netflix, Pinterest, and Uber.

Kotlin is the official programming language for Android but is also a powerful and reliable language that can be used for server-side applications.

It allows developers to write expressive and concise code that is fully compatible with Java-based technology stacks. Kotlin comes with a smooth learning curve – another reason for its popularity.

Read on to find out why Kotlin is a great choice for server-side development.

Support in Java ecosystem

Kotlin is fully interoperable with Java – one of the largest ecosystems in the programming world. You can use all frameworks and libraries without needing to recreate new ones.

This interoperability is one of the main reasons for the great success on Android. With Kotlin you can benefit from thousands of already existing Java frameworks, libraries, and dev adopters.

Here are some of the main benefits: 

  • Innovative language features – Kotlin supports delegated properties and type-safe builders which allow you to build easy-to-use and powerful abstractions.
  • Scalable – server-side applications built with Kotlin can be scaled to large numbers without big hardware requirements.
  • Fully interoperable with Java-based frameworks which allows you to use your familiar technology with a modern language.
  • Supports step-by-step migration – you can write new code in Kotlin but keep old parts in Java.
  • Framework-specific tooling, in addition to excellent IDE support.
  • Smooth learning curve – getting started with Kotlin is very easy for Java developers.
  • Reliable – the main reason behind Kotlin’s popularity is its reliability and performance.
  • Large community – it is expected that Kotlin will become one of the top 5 programming languages.

 Available frameworks for server-side development with Kotlin

  • Spring – offers more concise APIs and allows to generate a new project in Kotlin quickly.
  • Vert.x – a framework with dedicated support for building reactive web applications on the JVM.
  • Ktor – built by JetBrains framework for creating web applications in Kotlin, which uses coroutines for scalability and offers an easy-to-use API.
  • kotlinx.html – an alternative to traditional templating systems, can be used to build HTML in a web application.
  • Micronaut – a full-stack, JVM-based modern framework with a lot of built-in features for building easily testable modular microservice and serverless applications.
  • http4k – a functional toolkit for Kotlin HTTP applications.
  • Javalin – a very lightweight web framework for Java and Kotlin which supports HTTP 2, WebSockets, and async requests.

How to deploy Kotlin server-side applications

Web and mobile applications developed with Kotlin can be deployed on any host that supports Java applications, such as Google Cloud Platform, Amazon Web Services, and much more. You can follow the official Heroku tutorial to deploy Kotlin applications on Heroku.

There is also a series of tutorials provided by Google Cloud Platform you can use to learn more about the deployment of Kotlin applications to GCP, as well as an interactive code lab for the deployment of Kotlin Spring applications.