Transitioning from Java to Kotlin

Duncan McGregor and Nat Pryce, co-authors of Java to Kotlin: Refactoring Guidebook, speak with host Giovanni Asproni about their hands-on experiences migrating Java codebases. The episode starts by highlighting Kotlin’s seamless interoperability with Java, allowing teams to incrementally adopt Kotlin without disrupting existing Java code.

Duncan and Nat then describe some of the benefits of using Kotlin — including stronger type safety, non-nullable types, and better support for immutability — and some of the gotchas when refactoring from Java to Kotlin due to the different idioms supported by the two languages. Finally, they discuss the importance of testing and tooling, and the evolving role of AI-assisted tools in complex and large-scale refactorings — in the context of work done by teams, as opposed to individuals.

This episode is sponsored by Monday Dev