Maintainers

Subsystem ownership map. The data is derived from .space/CODEOWNERS (which uses JetBrains Space CODEOWNERS syntax — see reference/configuration.md) and from git log against master for the trailing 12+ months. Bot accounts are filtered.

The "Recent contributors" column shows the top 2-3 committers to that subsystem on master over the past one to two years; it is a quick guide to who recently worked on a given area, not a record of all maintainers.

Code ownership

Subsystem	Space team owner(s)	Recent contributors	Notes
FIR / K2 frontend (compiler/fir/)	"Kotlin Frontend"	Kirill Rakhman, Dmitriy Novozhilov, Mikhail Glukhikh	Most-active subsystem.
K1 frontend (compiler/frontend/, compiler/resolution/)	"Kotlin Frontend"	Dmitriy Novozhilov, Alexander Udalov	Maintenance + bug fixes.
PSI (compiler/psi/)	"Kotlin Frontend"	Dmitriy Novozhilov, Kirill Rakhman	Stable; rare changes.
Backend IR (compiler/ir/ir.tree/, compiler/ir/backend.common/)	"Kotlin Common Backend"	Ivan Kylchik, Sergej Jaskiewicz, Wojciech Litewka	Cross-target.
JVM backend (compiler/ir/backend.jvm/)	"Kotlin JVM"	Sergej Jaskiewicz, Ivan Kylchik	The default backend for most users.
JS backend (compiler/ir/backend.js/, js/)	"Kotlin JS"	Artem Kobzar, Ilya Goncharov, Zalim Bashorov
Wasm backend (compiler/ir/backend.wasm/, wasm/)	"Kotlin Wasm"	Ilya Goncharov, Artem Kobzar
Native backend (kotlin-native/, native/)	"Kotlin Native"	Alexander Shabalin, Igor Chevdar, Svyatoslav Scherbina, Dmitriy Dolovov, Vladimir Sukharev	Largest single subsystem after the frontend; includes the C/C++ runtime.
CLI (compiler/cli/, compiler/arguments/)	"Kotlin Compiler"	Dmitriy Novozhilov, Sergej Jaskiewicz, Alexander Udalov
Build Tools API (compiler/build-tools/)	"Build Tools API"	Yahor Berdnikau, Andrey Yastrebov, Timofey Solonin	Heavy churn; under active development.
Daemon (compiler/daemon/, compiler/incremental-compilation-impl/)	"Kotlin Build Tools"	Ilya Chernikov, Dmitriy Novozhilov, Alexander Udalov
Analysis API (analysis/)	"Kotlin Analysis API"	Dmitrii Gridin, Marco Pennekamp, Kirill Rakhman	Ka* prefix lives here.
Standard library (libraries/stdlib/)	"Kotlin Libraries"	Filipp Zhinkin, Ilya Gorbunov, Sergej Jaskiewicz
kotlin-reflect (libraries/reflect/)	"Kotlin Libraries"	Alexander Udalov, Dmitriy Novozhilov, Filipp Zhinkin	JVM-only.
kotlin-test (libraries/kotlin.test/)	"Kotlin Libraries"	Ilya Gorbunov, Sergej Jaskiewicz, Filipp Zhinkin
Scripting (libraries/scripting/)	"Kotlin Libraries"	Ilya Chernikov, Alexander Udalov, Dmitriy Novozhilov
Kotlin Gradle Plugin (libraries/tools/kotlin-gradle-plugin*)	"Kotlin Build Tools"	Yahor Berdnikau, Andrey Yastrebov, Timofey Solonin
Kotlin Maven Plugin (libraries/kotlin-maven-plugin*)	"Kotlin Build Tools"	Alexander Udalov, Dmitriy Novozhilov, Filipp Zhinkin
JPS (jps/)	"Kotlin Build Tools"	Ilya Chernikov, Alexander Udalov, Yahor Berdnikau
Compose plugin (plugins/compose/)	"Kotlin Compiler" + Compose team	Andrei Shikov, Dmitriy Novozhilov, Wojciech Litewka	Co-developed with Google's Compose team.
kotlinx.serialization plugin (plugins/kotlinx-serialization/)	"Kotlin Libraries"	Dmitriy Novozhilov, Leonid Startsev, Kirill Rakhman
kapt (plugins/kapt/)	"Kotlin Compiler"	Alexander Udalov, Dmitriy Novozhilov, Ilmir Usmanov
Parcelize (plugins/parcelize/)	"Kotlin Compiler"	Dmitriy Novozhilov, Kirill Rakhman, Rafal Galczak
allopen / noarg / sam-with-receiver / lombok (plugins/)	"Kotlin Compiler"	Dmitriy Novozhilov, Alexander Udalov, Kirill Rakhman	Small, related plugins.
Test infrastructure (compiler/test-infrastructure*, compiler/tests-common-new)	"Kotlin Compiler"	Dmitriy Novozhilov, Sergej Jaskiewicz, Mikhail Glukhikh
Build/CI (repo/, .teamcity/, gradle/)	"Kotlin Build Infrastructure"	Andrey Yastrebov, Yahor Berdnikau

Top-15 contributors over the past year

These are the most prolific human authors (excluding bots) on master over the past year. Numbers are commit counts. The list is unevenly distributed across subsystems — Analysis API, FIR, and KGP all have heavy committers near the top.

Author	Approx commits (1y)	Primary area
Dmitriy Novozhilov	970	FIR / cross-cutting
Dmitrii Gridin	890	Analysis API
Kirill Rakhman	640	FIR / Analysis API
Dmitriy Dolovov	480	Native
Mikhail Glukhikh	470	FIR
Vladimir Sukharev	440	Native
Ivan Kochurkin	360	Compiler / FIR
Sergej Jaskiewicz	320	IR / JVM
Ivan Kylchik	320	IR / JVM
Yahor Berdnikau	270	KGP / Build Tools
Nikolay Lunyak	250	(varied)
Alexander Udalov	230	Compiler / kapt / reflect
Grigorii Solnyshkin	220	(varied)
Andrey Yastrebov	220	KGP / Build Tools
Denis Zharkov	200	Frontend

How ownership is enforced

The CODEOWNERS file is checked at build time by org.jetbrains.kotlin.code.SpaceCodeOwnersTest. Every path under the repository root must be claimed by some owner (or marked UNKNOWN / NO_OWNER). When you add a new top-level directory or a new package, you also have to add the corresponding CODEOWNERS entry.

How to find the right reviewer

For most changes, the answer is: open a PR (or Space MR) and let the auto-assignment from CODEOWNERS find the right team. For large changes that span multiple subsystems, the convention is to ping the most-relevant owner directly on Slack (#kotlin-internal or the area-specific channels) ahead of opening the PR.