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Published: 30/11/2023

Which industries might benefit from employing Kotlin in their backend?

This article is sourced from Radosław Szmit’s Linkedin newsletter. If you want to delve deeper into the IT business and stay abreast of the latest updates, follow Radek on Linkedin for continuous insights!

From whom do insights come? 

At, Radek performs the role of Head of Growth and executes growth and business strategies for one of Europe’s fastest-growing software and AI companies. With over 14 years of experience in the IT industry, he has helped numerous clients and partners achieve their digital transformation goals and create value for their end customers.

Which industries might benefit from employing Kotlin in their backend?

#Kotlin is becoming increasingly popular among backend development programming languages. Some companies use it as a replacement for Java due to the easy transition process ensured by the interoperability with the existing #Java code.

In today’s “Software Development Insights” issue, I briefly cover how different industries adopt Kotlin for their backend and server-side operations. It may give you some initiative to consider switching or starting using Kotlin for your purposes.

Kotlin in FinTech

The finance sector can be an excellent environment for Kotlin to thrive in development. In #FinTech, it can aid in supporting hundreds of thousands of users simultaneously. The key features of Kotlin that are valued in the financial sector include the following:

  1. Safety – Null safety features in Kotlin language can aid in preventing common programming errors that can lead to severe consequences. In finance, this can be exceptionally costly. It helps to eliminate the jeopardy of null references from the code. For example, a typical property can’t hold a null value and will show a compile error. This allows us to catch the mistake and fix it accordingly.
  2. Expressiveness – Kotlin has a robust type system that catches errors at compile time, making writing reliable and secure code easier. This is particularly important in the FinTech industry, where security and reliability are critical. Kotlin makes a practical choice for developers to express complex financial algorithms and business logic that are easy to read and maintain.
  3. Conciseness – Kotlin is a great modern language with a concise syntax that can make creating complex financial applications easier. It helps to avoid and eliminate the need for problematic boilerplate code.
  4. Interoperability with Java – Kotlin being fully interoperable with Java, is one of its most versatile assets across different sectors. Since the financial industry has widely adopted Java as its primary language, it may be costly to replace it. Since Kotlin is fully compatible with the existing Java code, it can make a valuable tool for FinTech server-side applications with legacy codebases.
  5. Functional programming capabilities – Kotlin supports functional programming paradigms, which can help build complex financial systems. It supports higher-order functions, lambdas, and other practical programming concepts.

Some examples of companies using Kotlin in their backend in the finance sector are N26, ING, and American Express.

Kotlin in Marketplace

#Ecommerce and online marketplaces are essential branches of digital business sectors. Ensuring they can safely serve hundreds of thousands of users monthly is crucial to their operation. Using Kotlin for server-side backend and web development can help develop a stable platform users will happily implement.

Thanks to modern language features that help avoid common mistakes. Interoperability with Java makes it easy to use Kotlin with existing Java libraries. An experienced Java developer can adopt Kotlin easier. Thus hiring and outsourcing the developers can be more accessible.

One of the prime examples of companies that embraced Kotlin in their backend is Faire. The velocity of Kotlin features made developing their web application an exciting and preferable option.

The migration started by using the Java-to-Kotlin converter built into IntelliJ IDEA. It helped with revealing previously made assumptions about the nullability of different variables. The developers could overcome some of the issues via trial and error methods.

Their favorite Kotlin web development features included data class functions, a type system, read-only collections, and nullable annotations. Lambda expressions and type inference allowed for writing the desired code with appropriate necessary parts.

More marketplaces choose Kotlin for the backend.

DoorDash may be less of a proper marketplace; however, in some sense, it serves as a hub for food delivery services. They’ve decided to diversify their server operations into multiple backend services in Kotlin. It gave them tools to build a complex, scaleable platform. They were able to create a solid ecosystem based on JVM. Their favorite features include extension functions, data classes, function blocks, and coroutines.

Zalando, a fashion giant, adapted Kotlin in their backend through the Spring Boot framework. This versatile framework integrates well with Kotlin, is compatible with various application servers, and supports reactive programming via WebFlux. They are also considering the adoption of the Ktor framework in the future.

Other e-commerce platforms that use Kotlin for backend operations are Alibaba Group, South Korean Coupang, and an e-commerce giant – Wayfair.

Kotlin in Entertainment 

Kotlin for the backend also found its way into the #entertainment industry, specifically in #streaming and #gamedev.

Most streaming services like Netflix or gaming-oriented Twitch use it for mobile apps. Amazon uses Kotlin for their backend in Prime Video service. They used the features of Kotlin to create microservices for creating user profiles within the account.

Valuable functions like null safety, data classes, and first-class and extension features were the decisive factors facilitating Kotlin. Amazon developers also found the concise syntax and reduced code valuable.

Although Kotlin is not recommended for developing games in their core structure, some smaller productions like Horde, TetroCrate, Asteroid++, and Ore Infinium were created using Kotlin. The KorGE Game Engine offers a range of features for making games. They include a powerful editor embedded in IntelliJ IDE, a live debugger to live-debug your games, etc. Kotlin can deploy games on mobile, web, and desktop systems.

Besides developing games, Kotlin can be used for data storage features, like creating leaderboards within online games. It can also be adapted for various connected applications communicating quickly with a server.

Kotlin is solidifying its position among popular programming languages. Although it’s mostly known for mobile app development, thanks to its multiplatform functionalities, it can easily find its place in the backend and server-side development. Various industries can benefit from adopting Kotlin.

If the examples above sparked some inspiration for your current or new projects, we can help you build them. At, we have dedicated Kotlin experts that can help you develop your product. Don’t hesitate to contact us to see how we can help you.

Radosław Szmit
Radosław Szmit Head of Growth

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