At long last we have Kotlin first at Meta!
summary
Meta declares 10 million Kotlin lines across tens of thousands of modules and rolls out a Kotlin‑first policy that makes Kotlin the default for new Android code and starts automated Java→Kotlin conversion. A headless conversion pipeline plus reusable codemods and linters auto-apply fixes, turning what would take months across thousands of modules into days, while Android Studio and plugin profiling targets IDE freezes. Build work introduces class / source / source-only ABI modes and advocates K2 and KSP after finding compiler throughput and incremental ABI generation are the real bottlenecks.
AI-written summary · about
chapters (14)
- 0:00Introduction
- 1:09What Kotlin first means
- 2:33Current workflow and IDE challenges
- 5:25Code mode for refactoring
- 7:33Java to Kotlin conversion
- 10:05Progress mode and future features
- 12:55Java-Kotlin interaction issues
- 15:11Code review process improvements
- 18:02Build performance challenges
- 20:55Incremental build analysis
- 24:12Kotlin API vs Java API
- 27:29Build graph optimizations
- 33:07Single target optimizations
- 34:13Key takeaways
related talks
42mKotlin Adoption in the Giant Java Application
23mKotlin
31mWhat's new in Kotlin on Android, 2 years in
26mUpgrading Meta's Kotlin Infrastructure to K2
38mState of Kotlin for Android
43mKotlin: Next level of Android Development
20mState of Kotlin in Android
42mKotlin First – Taking Full Advantage of Kotlin For Android Development