Transitioning from Java to Kotlin in Backend Development

On October 3rd, Mercedes-Benz.io hosted Kotlin Lisboa Meetup #9 at its Lisbon office, focusing on immutability, static code analysis, and the transition from Java to Kotlin. Meetups like this highlight the value of knowledge sharing, as our teams and the wider community come together to learn, exchange ideas, and push the boundaries of software development. We are dedicated to fostering continuous learning and growth through shared expertise, which strengthens the innovation-driven culture we're so proud of.

The evening featured insightful presentations, including two by our fellow MB.ioneers. This is one of them.

In the fast-evolving landscape of backend development, companies are constantly seeking new technologies to streamline processes, enhance performance, and improve code quality. For years, Java has been the go-to language for backend development, particularly in large enterprise environments. However, Kotlin, a more concise and expressive language that integrates seamlessly with Java, has emerged as a game-changer. Today, Kotlin is not only the preferred choice for Android development but is also making significant strides in backend development.

Why Switch from Java to Kotlin?

Java’s longevity and widespread adoption make it seem irreplaceable. However, Kotlin offers key advantages that make it an attractive alternative, especially for teams looking to modernize their backend development practices.

1. Concise Syntax and Readability: Kotlin’s syntax is significantly more concise than Java, reducing boilerplate code and improving readability. This leads to faster development times and fewer chances for errors. Kotlin’s type inference, for example, allows you to write less code while making it more expressive.
2. Null Safety: One of the most touted features of Kotlin is its null safety. In Java, null pointer exceptions (NPEs) have been a notorious issue that can cause crashes and bugs. Kotlin addresses this problem by including null safety as a core language feature, allowing developers to avoid NPEs at compile time. By making nullability explicit in the type system, Kotlin significantly reduces runtime errors.
3. Interoperability with Java: One of the greatest strengths of Kotlin is its seamless interoperability with Java. Developers can gradually migrate their codebase from Java to Kotlin without having to rewrite everything at once. This allows teams to introduce Kotlin incrementally, leveraging its benefits without disrupting existing projects.

Industry Adoption of Kotlin for Backend Development

Kotlin has gained widespread popularity, like Amazon Web Services, DoorDash, Adobe, Expedia Group and more (more information here). These companies adopted Kotlin not only for its elegance but also for the tangible improvements it brings to code maintainability, performance, and team productivity.

Challenges and Considerations

While Kotlin brings numerous benefits, transitioning to a new language isn't without its challenges. Migrating from Java to Kotlin requires a mindset shift in development teams. Ensuring that all team members are comfortable with Kotlin’s syntax and features is crucial for a smooth transition.

Additionally, Kotlin’s growing ecosystem, while robust, is not yet as mature as Java's. Therefore, companies must evaluate whether Kotlin has the necessary library support for their specific use cases. Fortunately, Kotlin’s interoperability with Java ensures that developers can continue to use existing Java libraries and frameworks while gradually adopting Kotlin.

Future of Kotlin & Final Thoughts

Kotlin’s rise in the backend development space reflects a broader trend toward more modern, developer-friendly languages. With its blend of conciseness, safety, and interoperability, Kotlin is positioned to take on a larger role in enterprise development, challenging the status quo set by Java.

As more companies recognize the benefits of Kotlin, it’s likely that the language will continue to gain traction, especially for backend services where performance, scalability, and maintainability are key priorities.

While Kotlin was very much ahead of Java in early 2017 and 2018, the latest Java versions have significantly improved the language, making it a viable option once again. As both languages continue to evolve, it is crucial for development teams to continuously introspect and evaluate the right tools and technologies to ensure they meet their evolving needs.