google/mozc
Oct 2024 – Oct 2025
13 Months active
Languages Used
C++BazelProtocol BuffersPythonProtoStarlarkprotobufgyp
Technical Skills
Code MigrationRefactoringSoftware DesignAPI DesignAlgorithmsC++
Taku Kudo
PROFILE
Taku Kudo
Taku worked on modernizing and optimizing the google/mozc input method engine, focusing on prediction accuracy, architectural decoupling, and maintainability. Over 13 months, he delivered features such as unified prediction pipelines, cross-device caching, and robust user history management, while refactoring core data structures and APIs for safer, more modular code. Using C++ and Protocol Buffers, Taku migrated legacy components to modern patterns like absl::Span and AtomicSharedPtr, improved concurrency, and enhanced data validation with UTF-8 handling. His work reduced technical debt, streamlined testing, and enabled faster iteration, demonstrating deep expertise in software architecture, code refactoring, and performance optimization.
Overall Statistics
Feature vs Bugs
86%Features
Repository Contributions
228Total
Bugs
15
Commits
228
Features
91
Lines of code
68,573
Activity Months13
Your Network
4172 people
Work History
October 2025
19 Commits • 3 Features
Oct 1, 2025October 2025: Consolidated performance in google/mozc with major User History Predictor improvements, data integrity hardening, and UX refinements. Delivered cross-device full-sentence caching, inner segment boundary handling, and standardized history data management; removed legacy cache sizing logic and flags to streamline maintenance. Strengthened robustness with UTF-8 validity checks and crash prevention for history processing. Enhanced mobile UX via display_value support and reduced confusing suggestions. Achieved extensive code cleanup and centralized demotion logic for easier future evolution, improving maintainability and predictability across components.
19 Commits • 3 Features
Oct 1, 2025October 2025: Consolidated performance in google/mozc with major User History Predictor improvements, data integrity hardening, and UX refinements. Delivered cross-device full-sentence caching, inner segment boundary handling, and standardized history data management; removed legacy cache sizing logic and flags to streamline maintenance. Strengthened robustness with UTF-8 validity checks and crash prevention for history processing. Enhanced mobile UX via display_value support and reduced confusing suggestions. Achieved extensive code cleanup and centralized demotion logic for easier future evolution, improving maintainability and predictability across components.
October 2025
September 2025
24 Commits • 13 Features
Sep 1, 20252025-09 Monthly Summary for google/mozc: This period centered on fingerprint modernization, architecture decoupling, and data governance to boost search accuracy and system performance. Key features delivered include CityHash-based fingerprint modernization with CityFingerprint default usage in ExistenceFilter and 64-bit fingerprints; migration of legacy fingerprint references and deprecation of the slower 32-bit variant; and establishing independence of the existence-filter from specific fingerprint implementations. Additional enhancements include IsAvailalbe() support in the supplemental model; partial revert improvements with default enablement and updated bigram-chains; and broader improvements to mixed conversion, zero query suggestions, and candidate filtering. Data governance improvements removed the 62-day data-erasure window; ranking enhancements recently demoted short partial suggestions for result quality. API improvements include renaming GetResultType to IsValidResult, introducing a flag to control minimum value length for suppression, enabling post-corrections without inner segment boundary constraints, and simplifying Desktop candidate filtering. Major bugs fixed included removal of unused fingerprint functions to ensure CityHash compatibility and portability fixes such as switching hash results to size_t and addressing minor GetResultType semantics.
September 2025
24 Commits • 13 Features
Sep 1, 20252025-09 Monthly Summary for google/mozc: This period centered on fingerprint modernization, architecture decoupling, and data governance to boost search accuracy and system performance. Key features delivered include CityHash-based fingerprint modernization with CityFingerprint default usage in ExistenceFilter and 64-bit fingerprints; migration of legacy fingerprint references and deprecation of the slower 32-bit variant; and establishing independence of the existence-filter from specific fingerprint implementations. Additional enhancements include IsAvailalbe() support in the supplemental model; partial revert improvements with default enablement and updated bigram-chains; and broader improvements to mixed conversion, zero query suggestions, and candidate filtering. Data governance improvements removed the 62-day data-erasure window; ranking enhancements recently demoted short partial suggestions for result quality. API improvements include renaming GetResultType to IsValidResult, introducing a flag to control minimum value length for suppression, enabling post-corrections without inner segment boundary constraints, and simplifying Desktop candidate filtering. Major bugs fixed included removal of unused fingerprint functions to ensure CityHash compatibility and portability fixes such as switching hash results to size_t and addressing minor GetResultType semantics.
August 2025
27 Commits • 12 Features
Aug 1, 2025August 2025 — Mozc: architecture modernization, safety, and performance improvements across core pipeline and APIs. Delivered InnerSegments-based history access and front/back segment operations; completed Converter Attribute refactor to converter::Attributes; simplified key/value generation and number/prefix decomposition. Achieved performance and memory gains by removing lattice cache in favor of thread_local allocation and adopting absl::string_view and absl::StrAppend. Strengthened reliability with AtomicSharedPtr usage, node allocator cleanup, and API migrations (dep. convertwithnodeinfo, bnext/enext), plus guardrails like unified cache size (1024) and a flag to disable joined (bigram) predictions. Also fixed critical bugs: InValid() semantics, mobile multi-segment exact-match suppression, and automated G4 rollback.
27 Commits • 12 Features
Aug 1, 2025August 2025 — Mozc: architecture modernization, safety, and performance improvements across core pipeline and APIs. Delivered InnerSegments-based history access and front/back segment operations; completed Converter Attribute refactor to converter::Attributes; simplified key/value generation and number/prefix decomposition. Achieved performance and memory gains by removing lattice cache in favor of thread_local allocation and adopting absl::string_view and absl::StrAppend. Strengthened reliability with AtomicSharedPtr usage, node allocator cleanup, and API migrations (dep. convertwithnodeinfo, bnext/enext), plus guardrails like unified cache size (1024) and a flag to disable joined (bigram) predictions. Also fixed critical bugs: InValid() semantics, mobile multi-segment exact-match suppression, and automated G4 rollback.
August 2025
July 2025
17 Commits • 3 Features
Jul 1, 2025July 2025 monthly work summary for google/mozc. Focused on delivering measurable business value through feature enhancements, data structure refactors, and architecture modernization; improved prediction accuracy, undo capabilities, and end-to-end maintainability.
July 2025
17 Commits • 3 Features
Jul 1, 2025July 2025 monthly work summary for google/mozc. Focused on delivering measurable business value through feature enhancements, data structure refactors, and architecture modernization; improved prediction accuracy, undo capabilities, and end-to-end maintainability.
June 2025
19 Commits • 5 Features
Jun 1, 2025June 2025 Mozc (google/mozc) monthly summary focused on unifying and stabilizing the prediction engine across desktop and mobile, with a set of strategic refactors to reduce duplication, improve maintainability, and enable safer future iterations. The work delivered significant architectural and pipeline improvements, while also hardening the system with targeted bug fixes and parameter-driven configurability.
19 Commits • 5 Features
Jun 1, 2025June 2025 Mozc (google/mozc) monthly summary focused on unifying and stabilizing the prediction engine across desktop and mobile, with a set of strategic refactors to reduce duplication, improve maintainability, and enable safer future iterations. The work delivered significant architectural and pipeline improvements, while also hardening the system with targeted bug fixes and parameter-driven configurability.
June 2025
May 2025
21 Commits • 18 Features
May 1, 2025May 2025 — google/mozc: Delivered API stability and modularity improvements, targeted bug fixes, and migration-ready refactors. Implemented immutable argument support for Predictor and Rewriter finish and revert, decoupled Segments from core Predictor surfaces, modernized API typing with absl::Span, and performed major DictionaryPredictor cleanup with Bigram storage improvements. Also introduced deprecations and API renames to simplify maintenance, aligning with long-term code health. Result: more reliable suggestions/history, easier future migrations, and reduced technical debt.
May 2025
21 Commits • 18 Features
May 1, 2025May 2025 — google/mozc: Delivered API stability and modularity improvements, targeted bug fixes, and migration-ready refactors. Implemented immutable argument support for Predictor and Rewriter finish and revert, decoupled Segments from core Predictor surfaces, modernized API typing with absl::Span, and performed major DictionaryPredictor cleanup with Bigram storage improvements. Also introduced deprecations and API renames to simplify maintenance, aligning with long-term code health. Result: more reliable suggestions/history, easier future migrations, and reduced technical debt.
April 2025
20 Commits • 4 Features
Apr 1, 2025April 2025 performance highlights for google/mozc focused on delivering business value through architectural decoupling, concurrency improvements, and maintenance hygiene. Key outcomes include enabling direct use of ConversionRequest in predictors through Segments decoupling, system-wide thread-safety and performance optimizations, and a leaner build/test footprint with deprecated legacy features retired. The work emphasizes reliability, scalability, and faster iteration in predictor workflows, while reducing maintenance costs.
20 Commits • 4 Features
Apr 1, 2025April 2025 performance highlights for google/mozc focused on delivering business value through architectural decoupling, concurrency improvements, and maintenance hygiene. Key outcomes include enabling direct use of ConversionRequest in predictors through Segments decoupling, system-wide thread-safety and performance optimizations, and a leaner build/test footprint with deprecated legacy features retired. The work emphasizes reliability, scalability, and faster iteration in predictor workflows, while reducing maintenance costs.
April 2025
March 2025
25 Commits • 8 Features
Mar 1, 2025March 2025 (google/mozc) delivered a focused set of performance enhancements, stability improvements, and codebase simplifications to maximize end-user responsiveness and maintainability. The work emphasized near lock-free concurrency, safer APIs, and a smaller feature surface, enabling faster iteration and more predictable releases while reducing risk from deprecated components.
March 2025
25 Commits • 8 Features
Mar 1, 2025March 2025 (google/mozc) delivered a focused set of performance enhancements, stability improvements, and codebase simplifications to maximize end-user responsiveness and maintainability. The work emphasized near lock-free concurrency, safer APIs, and a smaller feature surface, enabling faster iteration and more predictable releases while reducing risk from deprecated components.
February 2025
30 Commits • 18 Features
Feb 1, 2025February 2025 highlights across google/mozc focused on modernization, safety, and performance improvements. The team delivered a comprehensive architecture refactor and API cleanup that reduces maintenance burden while unlocking faster development cycles. Key features include a Session/Engine interface refactor with EngineConverter and reduced EngineOutput coupling, pointer/ownership modernization, and config handling via shared_ptr with a modernized ConfigHandler API. Additional work covers incognito mode support with lazy initialization, relocation of TransliteratorInterface to internal scope, and data handling refinements (HashOf for Table, ImeContext CopyableData) to improve correctness and performance. Cleanup efforts such as removal of usage_stats, tiny_storage/registry, and deprecated APIs further streamline the codebase and testing. Major impact areas include improved concurrency with std::atomic-based synchronization for the Connector cache, safer ownership models, reduced API surface, and clearer business value through more reliable input processing and faster iteration cycles.
30 Commits • 18 Features
Feb 1, 2025February 2025 highlights across google/mozc focused on modernization, safety, and performance improvements. The team delivered a comprehensive architecture refactor and API cleanup that reduces maintenance burden while unlocking faster development cycles. Key features include a Session/Engine interface refactor with EngineConverter and reduced EngineOutput coupling, pointer/ownership modernization, and config handling via shared_ptr with a modernized ConfigHandler API. Additional work covers incognito mode support with lazy initialization, relocation of TransliteratorInterface to internal scope, and data handling refinements (HashOf for Table, ImeContext CopyableData) to improve correctness and performance. Cleanup efforts such as removal of usage_stats, tiny_storage/registry, and deprecated APIs further streamline the codebase and testing. Major impact areas include improved concurrency with std::atomic-based synchronization for the Connector cache, safer ownership models, reduced API surface, and clearer business value through more reliable input processing and faster iteration cycles.
February 2025
January 2025
7 Commits • 1 Features
Jan 1, 2025January 2025: Focused on engine and session architecture refactor and cleanup in google/mozc to enhance modularity, reliability, and long-term maintainability. Completed removal of deprecated interfaces and internal directories, reduced coupling by moving SessionConverter to the engine layer, and decoupling engine from converters and segments. Implemented robust initialization approach for UserDictionarySessionHandler to improve reliability without incurring unnecessary startup costs. These changes pave the way for faster feature delivery and easier future optimizations.
January 2025
7 Commits • 1 Features
Jan 1, 2025January 2025: Focused on engine and session architecture refactor and cleanup in google/mozc to enhance modularity, reliability, and long-term maintainability. Completed removal of deprecated interfaces and internal directories, reduced coupling by moving SessionConverter to the engine layer, and decoupling engine from converters and segments. Implemented robust initialization approach for UserDictionarySessionHandler to improve reliability without incurring unnecessary startup costs. These changes pave the way for faster feature delivery and easier future optimizations.
December 2024
15 Commits • 4 Features
Dec 1, 2024December 2024, google/mozc: Key features delivered focused on architectural modernization, data-loading modernization, processing efficiency, and data-migration cleanup. Major bugs fixed by removing brittle dependencies, consolidating interfaces, and simplifying data paths. Overall impact: leaner, more modular engine with safer ownership, reduced maintenance burden, and improved startup and data-loading performance. Technologies demonstrated: modern C++ patterns, Abseil types, data-loader design, API surface reduction, and robust lifecycle management.
15 Commits • 4 Features
Dec 1, 2024December 2024, google/mozc: Key features delivered focused on architectural modernization, data-loading modernization, processing efficiency, and data-migration cleanup. Major bugs fixed by removing brittle dependencies, consolidating interfaces, and simplifying data paths. Overall impact: leaner, more modular engine with safer ownership, reduced maintenance burden, and improved startup and data-loading performance. Technologies demonstrated: modern C++ patterns, Abseil types, data-loader design, API surface reduction, and robust lifecycle management.
December 2024
November 2024
3 Commits • 1 Features
Nov 1, 2024November 2024 monthly summary for google/mozc: Delivered a feature to improve zero-query suggestion quality by reranking with a neutral classifier. This feature integrates into DictionaryPredictor and introduces a new virtual method in SupplementalModelInterface to support the classifier-based reranking, plus corresponding mock support. Interface refactors to enable more flexible candidate insertion: replaced pointer-based Result handling with absl::Span<Result>, and removed direct reliance on Result pointers to allow insertion of new candidates in the supplemental model.
November 2024
3 Commits • 1 Features
Nov 1, 2024November 2024 monthly summary for google/mozc: Delivered a feature to improve zero-query suggestion quality by reranking with a neutral classifier. This feature integrates into DictionaryPredictor and introduces a new virtual method in SupplementalModelInterface to support the classifier-based reranking, plus corresponding mock support. Interface refactors to enable more flexible candidate insertion: replaced pointer-based Result handling with absl::Span<Result>, and removed direct reliance on Result pointers to allow insertion of new candidates in the supplemental model.
October 2024
1 Commits • 1 Features
Oct 1, 2024Concise monthly summary for 2024-10 for google/mozc focusing on key accomplishments, business value, and technical achievement. The main delivery this month was the Typing Correction System Overhaul in the typing pipeline, including API modernization and refactoring efforts. This work reduces technical debt and positions the project for easier future enhancements and improved user experience.
1 Commits • 1 Features
Oct 1, 2024Concise monthly summary for 2024-10 for google/mozc focusing on key accomplishments, business value, and technical achievement. The main delivery this month was the Typing Correction System Overhaul in the typing pipeline, including API modernization and refactoring efforts. This work reduces technical debt and positions the project for easier future enhancements and improved user experience.
October 2024
Activity
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Quality Metrics
Correctness93.0%
Maintainability91.8%
Architecture90.2%
Performance84.6%
AI Usage20.0%
Skills & Technologies
Programming Languages
BazelC++ProtoProtocol BuffersPythonStarlarkgypprotobuf
Technical Skills
API DesignAPI MigrationAccess ControlAlgorithmAlgorithm DesignAlgorithm ImplementationAlgorithm OptimizationAlgorithm RefinementAlgorithm SelectionAlgorithmsAsynchronous ProgrammingBazelBug FixBug FixingBuild System Configuration
Repositories Contributed To
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