Kotlin 2.3.21: The Release That Finally Makes KMP Build Performance Predictable Kotlin 2.3.21 is one of those releases you don’t notice from the changelog, but you feel immediately if you work with Kotlin Multiplatform in production. It doesn’t introduce flashy language features — it fixes the stuff that quietly destroys developer productivity: broken incremental builds, unstable Wasm compilation, and fragile iOS linking via SPM. For teams building high-load systems, shared codebases, or multi-target apps (Android, iOS, WebAssembly), this release is less about “new Kotlin features” and more about restoring trust in the build system. The K2 compiler finally behaves like a stable foundation instead of experimental infrastructure. Kotlin Wasm incremental build performance improvements One of the biggest pain points in Kotlin/Wasm was unpredictable incremental compilation. A small change in a shared module could trigger full rebuilds or backend failures due to klib metadata invalidation.…