JetBrains/intellij-scala
Oct 2024 – Apr 2026
17 Months active
Languages Used
JavaPropertiesScalaKotlin
Technical Skills
Code AnalysisCompiler DevelopmentCompiler InternalsCompiler PluginsIDE DevelopmentIDE Plugin Development
Andrei Sugak
PROFILE
Andrei Sugak
Over 17 months, contributed to JetBrains/intellij-scala by building and refining core features for Scala 3 support in the IntelliJ Scala plugin. Focused on type resolution, implicit scope handling, and method inference, the work addressed complex language features such as named type arguments, intersection types, and kind-projector support. Leveraged Java, Kotlin, and Scala to implement robust parsing, code analysis, and plugin infrastructure, while maintaining cross-version compatibility and enhancing code completion and error diagnostics. Emphasized test-driven development and regression safety, expanding automated test coverage and improving decompiler accuracy. These efforts improved IDE reliability, developer productivity, and migration paths for Scala projects.
Overall Statistics
Feature vs Bugs
56%Features
Repository Contributions
139Total
Bugs
20
Commits
139
Features
25
Lines of code
1,192,563
Activity Months17
Your Network
710 peopleSame Organization
@jetbrains.com676
Shared Repositories
34
Aleksandra ZdrojowaMember
Aleksandra ZdrojowaMember
Andrey PshenkinMember
Antoni GrodowskiMember
AlexanderMember
builduser-scalaMember
builduserMember
Dale WijnandMember
Dmitrii NaumenkoMember
Work History
April 2026
20 Commits • 3 Features
Apr 1, 2026April 2026 delivered substantial Scala 3 language support improvements and end-to-end named type arguments tooling for JetBrains/intellij-scala, along with robustness enhancements to reference resolution tests. The work accelerates Scala 3 adoption, strengthens code intelligence (parameter resolution, implicit search, and erased modifier handling), improves Kotlin interop, and enhances maintainability through targeted refactors and clearer type parameter rendering.
20 Commits • 3 Features
Apr 1, 2026April 2026 delivered substantial Scala 3 language support improvements and end-to-end named type arguments tooling for JetBrains/intellij-scala, along with robustness enhancements to reference resolution tests. The work accelerates Scala 3 adoption, strengthens code intelligence (parameter resolution, implicit search, and erased modifier handling), improves Kotlin interop, and enhances maintainability through targeted refactors and clearer type parameter rendering.
April 2026
March 2026
22 Commits • 3 Features
Mar 1, 2026March 2026 monthly summary for JetBrains/intellij-scala focusing on resolution/typing improvements, SAM adaptation, and cross-language interop, with targeted rollbacks to stabilize the subsystem. The work delivered reduces false overload resolution ambiguities, enhances Scala 3 overload handling, and improves maintainability and Kotlin interop, delivering measurable business value while maintaining engineering stability.
March 2026
22 Commits • 3 Features
Mar 1, 2026March 2026 monthly summary for JetBrains/intellij-scala focusing on resolution/typing improvements, SAM adaptation, and cross-language interop, with targeted rollbacks to stabilize the subsystem. The work delivered reduces false overload resolution ambiguities, enhances Scala 3 overload handling, and improves maintainability and Kotlin interop, delivering measurable business value while maintaining engineering stability.
February 2026
8 Commits • 2 Features
Feb 1, 2026February 2026 monthly summary for JetBrains/intellij-scala focused on Scala 3 interoperability, type safety, and build efficiency. Implemented targeted compiler/semantics improvements and bug fixes that reduce compile-time issues and improve reliability for modern Scala usage. Business value accrues from safer implicit resolution, safer type equality checks, and reduced unnecessary work on stdLib patches across Scala versions.
8 Commits • 2 Features
Feb 1, 2026February 2026 monthly summary for JetBrains/intellij-scala focused on Scala 3 interoperability, type safety, and build efficiency. Implemented targeted compiler/semantics improvements and bug fixes that reduce compile-time issues and improve reliability for modern Scala usage. Business value accrues from safer implicit resolution, safer type equality checks, and reduced unnecessary work on stdLib patches across Scala versions.
February 2026
January 2026
1 Commits
Jan 1, 2026January 2026 focused on stabilizing the IntelliJ Scala plugin's annotator to improve reliability and correctness of Scala type-bound analysis. Delivered a targeted bug fix that restores missing property in ScTypeBoundsOwnerAnnotator, enhancing editor reliability for Scala developers across the JetBrains IDE ecosystem.
January 2026
1 Commits
Jan 1, 2026January 2026 focused on stabilizing the IntelliJ Scala plugin's annotator to improve reliability and correctness of Scala type-bound analysis. Delivered a targeted bug fix that restores missing property in ScTypeBoundsOwnerAnnotator, enhancing editor reliability for Scala developers across the JetBrains IDE ecosystem.
November 2025
3 Commits • 1 Features
Nov 1, 2025November 2025: Focused on stabilizing Scala annotations and cross-version syntax in the JetBrains IntelliJ Scala plugin (intellij-scala). Key features delivered include cross-version support for nullary method invocations (Scala 2/3), improving code readability and compatibility. Major bugs fixed encompass enhanced default parameter handling and error reporting in the Scala Annotator, with improved substitutor and implicit conversion handling for Scala 3 files. These changes collectively improve type-safety, developer experience, and cross-version compatibility in Scala projects. Technologies/skills demonstrated include advanced Scala type system awareness, annotation processing, implicit resolution, and cross-version compatibility strategies.
3 Commits • 1 Features
Nov 1, 2025November 2025: Focused on stabilizing Scala annotations and cross-version syntax in the JetBrains IntelliJ Scala plugin (intellij-scala). Key features delivered include cross-version support for nullary method invocations (Scala 2/3), improving code readability and compatibility. Major bugs fixed encompass enhanced default parameter handling and error reporting in the Scala Annotator, with improved substitutor and implicit conversion handling for Scala 3 files. These changes collectively improve type-safety, developer experience, and cross-version compatibility in Scala projects. Technologies/skills demonstrated include advanced Scala type system awareness, annotation processing, implicit resolution, and cross-version compatibility strategies.
November 2025
October 2025
9 Commits • 1 Features
Oct 1, 2025Month 2025-10 focused on stabilizing and advancing the JetBrains intellij-scala plugin with critical bug fixes and Scala 3 feature support. Delivered two major momentum items in JetBrains/intellij-scala, improving correctness, compatibility, and implicit resolution and enabling broader Scala 3 adoption in the IDE.
October 2025
9 Commits • 1 Features
Oct 1, 2025Month 2025-10 focused on stabilizing and advancing the JetBrains intellij-scala plugin with critical bug fixes and Scala 3 feature support. Delivered two major momentum items in JetBrains/intellij-scala, improving correctness, compatibility, and implicit resolution and enabling broader Scala 3 adoption in the IDE.
September 2025
10 Commits • 2 Features
Sep 1, 2025September 2025 performance summary for JetBrains/intellij-scala. Delivered targeted IDE enhancements for Scala 3 type parameter extraction and polymorphic inference, reinforced PolyFunction support in the Scala plugin, and addressed focused bug fixes and test quality improvements. These updates improved code completion accuracy and error highlighting, increased test coverage for Scala 3 scenarios, and reduced maintenance friction, delivering measurable business value through faster development and more reliable tooling.
10 Commits • 2 Features
Sep 1, 2025September 2025 performance summary for JetBrains/intellij-scala. Delivered targeted IDE enhancements for Scala 3 type parameter extraction and polymorphic inference, reinforced PolyFunction support in the Scala plugin, and addressed focused bug fixes and test quality improvements. These updates improved code completion accuracy and error highlighting, increased test coverage for Scala 3 scenarios, and reduced maintenance friction, delivering measurable business value through faster development and more reliable tooling.
September 2025
August 2025
2 Commits • 1 Features
Aug 1, 2025Month: 2025-08 | Repository: JetBrains/intellij-scala | This month delivered critical features and fixes for the IntelliJ Scala plugin, improving alignment with newer Scala features and the reliability of decompiler outputs. Key feature: Kind Projector option support in IntelliJ Scala, enabling -Xkind-projector and -Ykind-projector, with updates to type presentation logic and module settings and accompanying tests. Major bug fix: shared types caching in the Scala decompiler corrected by updating the stub version, simplifying the caching key, and adding a derivation API test. Impact: closer parity with Scala 3.5+ in IDE behavior, more accurate type displays, reduced regression risk, and better test coverage. Technologies/skills demonstrated: Kotlin/Java plugin development, decompiler internals, caching strategies, tests and test-driven development, and integration of compiler options into IDE configuration.
August 2025
2 Commits • 1 Features
Aug 1, 2025Month: 2025-08 | Repository: JetBrains/intellij-scala | This month delivered critical features and fixes for the IntelliJ Scala plugin, improving alignment with newer Scala features and the reliability of decompiler outputs. Key feature: Kind Projector option support in IntelliJ Scala, enabling -Xkind-projector and -Ykind-projector, with updates to type presentation logic and module settings and accompanying tests. Major bug fix: shared types caching in the Scala decompiler corrected by updating the stub version, simplifying the caching key, and adding a derivation API test. Impact: closer parity with Scala 3.5+ in IDE behavior, more accurate type displays, reduced regression risk, and better test coverage. Technologies/skills demonstrated: Kotlin/Java plugin development, decompiler internals, caching strategies, tests and test-driven development, and integration of compiler options into IDE configuration.
July 2025
3 Commits • 2 Features
Jul 1, 2025Monthly summary for 2025-07: Focused delivery on core type resolution and robustness for Scala tooling in JetBrains/intellij-scala. Delivered enhancements to implicit resolution with aggressive candidate filtering, improving accuracy and performance in Scala 3 files; added robustness for derives clause annotations when companion objects are missing by introducing a fallback fake companion module; and refactored the Scala decompiler and DerivesUtil to improve type caching accuracy by parameterizing sharedTypes cache keys by the parent node and adjusting companion object retrieval logic. These changes reduce ambiguity in implicit resolution, improve resolution reliability in edge cases, and enhance overall performance of type caching and decompilation workflows.
3 Commits • 2 Features
Jul 1, 2025Monthly summary for 2025-07: Focused delivery on core type resolution and robustness for Scala tooling in JetBrains/intellij-scala. Delivered enhancements to implicit resolution with aggressive candidate filtering, improving accuracy and performance in Scala 3 files; added robustness for derives clause annotations when companion objects are missing by introducing a fallback fake companion module; and refactored the Scala decompiler and DerivesUtil to improve type caching accuracy by parameterizing sharedTypes cache keys by the parent node and adjusting companion object retrieval logic. These changes reduce ambiguity in implicit resolution, improve resolution reliability in edge cases, and enhance overall performance of type caching and decompilation workflows.
July 2025
June 2025
10 Commits • 3 Features
Jun 1, 2025June 2025 summary for JetBrains/intellij-scala focusing on improving Scala 3 readiness and developer UX. Delivered robust features for Scala 3 using-clauses and implicit resolution, enhanced inlay hints for complex signatures, and added Mirror derivation support. Stabilized correctness with targeted fixes and expanded test coverage across multiple modules, ensuring a refactor-safe baseline for future Scala 3 enhancements.
June 2025
10 Commits • 3 Features
Jun 1, 2025June 2025 summary for JetBrains/intellij-scala focusing on improving Scala 3 readiness and developer UX. Delivered robust features for Scala 3 using-clauses and implicit resolution, enhanced inlay hints for complex signatures, and added Mirror derivation support. Stabilized correctness with targeted fixes and expanded test coverage across multiple modules, ensuring a refactor-safe baseline for future Scala 3 enhancements.
May 2025
2 Commits
May 1, 2025May 2025 (2025-05) focused on stabilizing the JetBrains/intellij-scala plugin by addressing two high-impact resolution issues and expanding test coverage. Delivered targeted bug fixes for kind-projector resolution under -Ykind-projector (including the -Ykind-projector:underscores variant) and corrected a typo in a resolution-related method name. Fixed resolution of Scala 3 'using' clauses in implicit classes, adjusting parameter clause rendering/processing to correctly handle both 'implicit' and 'using' forms. Added comprehensive tests to cover both fixes, preventing regressions. Impact: improved IDE code insight and reliability for Scala developers relying on kind-projector and Scala 3 features, reduced UX friction in plugin resolution. Technologies/skills demonstrated: IntelliJ plugin development, Scala plugin internals, test-driven development, and regression testing. Key commits: d3973af3948e83c1837dcaa91c9dc922c78a0ada (resolve: Fix resolve of kind-projector synthetics with -Ykind-projector) and f826df1d9822bb2f1410466ca68d45e8ee18753c (resolve: Fix resolve of implicit classes with using clauses).
2 Commits
May 1, 2025May 2025 (2025-05) focused on stabilizing the JetBrains/intellij-scala plugin by addressing two high-impact resolution issues and expanding test coverage. Delivered targeted bug fixes for kind-projector resolution under -Ykind-projector (including the -Ykind-projector:underscores variant) and corrected a typo in a resolution-related method name. Fixed resolution of Scala 3 'using' clauses in implicit classes, adjusting parameter clause rendering/processing to correctly handle both 'implicit' and 'using' forms. Added comprehensive tests to cover both fixes, preventing regressions. Impact: improved IDE code insight and reliability for Scala developers relying on kind-projector and Scala 3 features, reduced UX friction in plugin resolution. Technologies/skills demonstrated: IntelliJ plugin development, Scala plugin internals, test-driven development, and regression testing. Key commits: d3973af3948e83c1837dcaa91c9dc922c78a0ada (resolve: Fix resolve of kind-projector synthetics with -Ykind-projector) and f826df1d9822bb2f1410466ca68d45e8ee18753c (resolve: Fix resolve of implicit classes with using clauses).
May 2025
April 2025
11 Commits • 1 Features
Apr 1, 2025April 2025 performance summary for JetBrains/intellij-scala. Delivered comprehensive Scala plugin enhancements for type resolution, inference, and method resolution across Scala 2/3, along with targeted fixes addressing critical resolution bugs. The work improved IDE accuracy, reliability, and cross-version support, leading to faster code navigation and fewer false positives for Scala developers. Key improvements include stronger type parameter handling, pattern type inference recursion fixes, eta-expansion enhancements, and Scala 3 extension support, complemented by robust caching and stability improvements.
April 2025
11 Commits • 1 Features
Apr 1, 2025April 2025 performance summary for JetBrains/intellij-scala. Delivered comprehensive Scala plugin enhancements for type resolution, inference, and method resolution across Scala 2/3, along with targeted fixes addressing critical resolution bugs. The work improved IDE accuracy, reliability, and cross-version support, leading to faster code navigation and fewer false positives for Scala developers. Key improvements include stronger type parameter handling, pattern type inference recursion fixes, eta-expansion enhancements, and Scala 3 extension support, complemented by robust caching and stability improvements.
March 2025
3 Commits • 2 Features
Mar 1, 2025March 2025 monthly summary for JetBrains/intellij-scala: Delivered core plugin enhancements focusing on robust method and constructor resolution, and clarified compatibility semantics. Key architectural improvements centralized resolution logic in MethodResolveProcessor, enabling accurate handling of complex types and overloads, and renamed and clarified compatibility checks (checkConstructorConformance -> checkConstructorApplicability) with updated product-facing result type aliases. These changes improve code reliability, maintainability, and user experience for Scala code navigation in the IntelliJ platform. Technologies demonstrated include advanced refactoring, encapsulation, and IntelliJ Platform plugin development patterns (Java/Kotlin), with a focus on code quality and performance. Business value: reduces resolution errors in complex Scala code, improves IDE reliability and user productivity, and lays the groundwork for faster feature delivery and easier future maintenance.
3 Commits • 2 Features
Mar 1, 2025March 2025 monthly summary for JetBrains/intellij-scala: Delivered core plugin enhancements focusing on robust method and constructor resolution, and clarified compatibility semantics. Key architectural improvements centralized resolution logic in MethodResolveProcessor, enabling accurate handling of complex types and overloads, and renamed and clarified compatibility checks (checkConstructorConformance -> checkConstructorApplicability) with updated product-facing result type aliases. These changes improve code reliability, maintainability, and user experience for Scala code navigation in the IntelliJ platform. Technologies demonstrated include advanced refactoring, encapsulation, and IntelliJ Platform plugin development patterns (Java/Kotlin), with a focus on code quality and performance. Business value: reduces resolution errors in complex Scala code, improves IDE reliability and user productivity, and lays the groundwork for faster feature delivery and easier future maintenance.
March 2025
February 2025
12 Commits • 2 Features
Feb 1, 2025February 2025 — JetBrains/intellij-scala focused on strengthening Scala 3 support in the IDE to improve developer productivity and code correctness. Key features delivered include: 1) Scala 3 implicit resolution and type inference improvements across nested scopes, with refined handling of package prefixes and type parameter bounds to reduce false positives and improve ambiguity resolution; 2) Scala 3 intersection/self-types and compound types support, including improved representation, resolution, and decompiler printing; 3) Robustness improvements for exported type definitions typing and resolution to ensure correct associations with signatures; 4) F-bounded types and type parameter annotation handling improvements with added validation tests. Major bugs fixed include: fixes to typing of exported type definitions and enhancements to f-bounded type handling and implicit annotation enforcement. Overall impact: increased accuracy and reliability of code analysis for Scala 3, smoother migration path, and higher developer productivity through fewer navigation and inference issues. Technologies/skills demonstrated: Scala 3 type system (implicit resolution, type inference, intersection/self-types, compound types), decompiler tooling, code analysis, type parameter handling, and test modernization.
February 2025
12 Commits • 2 Features
Feb 1, 2025February 2025 — JetBrains/intellij-scala focused on strengthening Scala 3 support in the IDE to improve developer productivity and code correctness. Key features delivered include: 1) Scala 3 implicit resolution and type inference improvements across nested scopes, with refined handling of package prefixes and type parameter bounds to reduce false positives and improve ambiguity resolution; 2) Scala 3 intersection/self-types and compound types support, including improved representation, resolution, and decompiler printing; 3) Robustness improvements for exported type definitions typing and resolution to ensure correct associations with signatures; 4) F-bounded types and type parameter annotation handling improvements with added validation tests. Major bugs fixed include: fixes to typing of exported type definitions and enhancements to f-bounded type handling and implicit annotation enforcement. Overall impact: increased accuracy and reliability of code analysis for Scala 3, smoother migration path, and higher developer productivity through fewer navigation and inference issues. Technologies/skills demonstrated: Scala 3 type system (implicit resolution, type inference, intersection/self-types, compound types), decompiler tooling, code analysis, type parameter handling, and test modernization.
January 2025
4 Commits
Jan 1, 2025January 2025 (2025-01) focused on stabilizing Scala type inference in the JetBrains IntelliJ Scala plugin. Delivered consolidated fixes to type inference for chained apply calls and context functions, optimized handling of expected types, and improved resolution of extension methods with type parameters. Removed an ad-hoc UndefinedType preservation to rely on standard substitution, strengthening robustness across scenarios. These changes reduce developer friction by improving correctness of code completion and inference, and contribute to smoother project maintenance and onboarding.
4 Commits
Jan 1, 2025January 2025 (2025-01) focused on stabilizing Scala type inference in the JetBrains IntelliJ Scala plugin. Delivered consolidated fixes to type inference for chained apply calls and context functions, optimized handling of expected types, and improved resolution of extension methods with type parameters. Removed an ad-hoc UndefinedType preservation to rely on standard substitution, strengthening robustness across scenarios. These changes reduce developer friction by improving correctness of code completion and inference, and contribute to smoother project maintenance and onboarding.
January 2025
November 2024
6 Commits • 1 Features
Nov 1, 2024November 2024 monthly summary for JetBrains/intellij-scala focused on delivering targeted Scala 3 improvements and hardening type-resolution paths. Key work centered on enhancing the Scala Import Optimizer for implicitly added derived methods and fortifying the resolver/conformance pipeline against complex type scenarios. Delivered changes reduce incorrect imports, improve reliability when using derived methods, and strengthen edge-case handling around apply resolution, type parameters, and shape resolution.
November 2024
6 Commits • 1 Features
Nov 1, 2024November 2024 monthly summary for JetBrains/intellij-scala focused on delivering targeted Scala 3 improvements and hardening type-resolution paths. Key work centered on enhancing the Scala Import Optimizer for implicitly added derived methods and fortifying the resolver/conformance pipeline against complex type scenarios. Delivered changes reduce incorrect imports, improve reliability when using derived methods, and strengthen edge-case handling around apply resolution, type parameters, and shape resolution.
October 2024
13 Commits • 1 Features
Oct 1, 2024In 2024-10, JetBrains/intellij-scala delivered substantive Scala 3 support enhancements and critical bug fixes in the IntelliJ plugin. Key work included fixes for type equivalence checks when abstract types have Nothing as an upper bound and improvements to type alias conformance, with the addition of tests (TypeAliasScala3ConformanceTest). The feature set for Scala 3 givens, context bounds, and type member support was implemented, including a deprecation path, quick fixes, deferred givens checks, and new parsing/annotator support—along with extensive updates to stubs, test harnesses, and PSI generation for context bounds. The work involved a broad set of commits across both bug and feature areas (e.g., for givens, context bounds, parsing, and tests), reflecting end-to-end validation from parsing to user-visible diagnostics. Overall, these changes enhance type-analysis accuracy, code completion, and navigation for Scala 3 code, accelerating migration and reducing debugging time within the IDE. Technologies demonstrated include IntelliJ Platform development (PSI, stubs, parsers, annotators), Kotlin/Java plugin work, and test-driven validation.
13 Commits • 1 Features
Oct 1, 2024In 2024-10, JetBrains/intellij-scala delivered substantive Scala 3 support enhancements and critical bug fixes in the IntelliJ plugin. Key work included fixes for type equivalence checks when abstract types have Nothing as an upper bound and improvements to type alias conformance, with the addition of tests (TypeAliasScala3ConformanceTest). The feature set for Scala 3 givens, context bounds, and type member support was implemented, including a deprecation path, quick fixes, deferred givens checks, and new parsing/annotator support—along with extensive updates to stubs, test harnesses, and PSI generation for context bounds. The work involved a broad set of commits across both bug and feature areas (e.g., for givens, context bounds, parsing, and tests), reflecting end-to-end validation from parsing to user-visible diagnostics. Overall, these changes enhance type-analysis accuracy, code completion, and navigation for Scala 3 code, accelerating migration and reducing debugging time within the IDE. Technologies demonstrated include IntelliJ Platform development (PSI, stubs, parsers, annotators), Kotlin/Java plugin work, and test-driven validation.
October 2024
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Quality Metrics
Correctness91.4%
Maintainability84.0%
Architecture84.2%
Performance79.2%
AI Usage25.8%
Skills & Technologies
Programming Languages
JavaKotlinPropertiesScala
Technical Skills
API DevelopmentAutomated TestingBackend DevelopmentCode AnalysisCode AnnotationCode DocumentationCode InsightCode InspectionCode RefactoringCode ResolutionCompiler DesignCompiler DevelopmentCompiler InternalsCompiler Plugin DevelopmentCompiler Plugins
Repositories Contributed To
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