Why Meta is moving its android apps from java to kotlin

Engineers at Facebook parent meta have detailed their multi-year effort to convert the codebases from java to kotlin

That's a large task for a company with thousands of web developers and android developers

The migration is underway, with Meta's android app which consists of 10 million lines of code

Meta's switch from Java to kotlin for android application development is a milestone

Despite the benefits of kotlin that motivated Meta's switch but still there are some demerits that make the move risky

Firstly, there is a large gap in popularity between Java and kotlin ,this includes the complexity and interoperability 

Kotlin is a popular programming language but compared to java the popularity gap is clear.

Here the biggest concern with Meta's switch is that slower build times in Kotlin versus Java

Meta engineers have decided to convert almost all their codebases into Kotlin rather than writing new code using kotlin

There is good news for budding developers as well. The Meta has released several in-house Kotlin conversion tools on GitHub

A Facebook engineer detailed last year, that while Kotlin adaption can be smooth, it is difficult at scale 

So far, Meta has on average seen an 11% reduction in the size of its codebase. 

The Google Home Team has reported a 33% reduction in its app codebase while migrating

Google's Kotlin product manager says we are so excited to see Meta make the move to Kotlin and are glad they've had success.