ydb-platform/ydb
Jun 2025 – Mar 2026
10 Months active
Languages Used
C++PythonMarkdown
Technical Skills
Algorithm ImplementationBackend DevelopmentDatabaseDatabase InternalsDistributed SystemsQuery Optimization
Filitov Mikhail
PROFILE
Filitov Mikhail
Worked on the ydb-platform/ydb repository, delivering advanced query processing features and performance optimizations over ten months. Developed and refined block hash join algorithms, implemented SIMD-based and scalar join paths, and enhanced memory management for large-scale data workloads. Applied C++ and Python to optimize backend systems, improve error handling, and ensure platform-specific compatibility across Linux and macOS. Contributed to system reliability by fixing concurrency issues, stabilizing test suites, and expanding benchmarking capabilities. Documented complex features for users and operators, while integrating deep memory profiling and configurable join strategies. Demonstrated expertise in algorithm design, distributed systems, and low-level performance engineering.
Overall Statistics
Feature vs Bugs
67%Features
Repository Contributions
43Total
Bugs
9
Commits
43
Features
18
Lines of code
9,341
Activity Months10
Your Network
479 peopleShared Repositories
479
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Work History
March 2026
3 Commits • 3 Features
Mar 1, 2026Monthly summary for 2026-03 focusing on delivering memory profiling enhancements, observability improvements, and configurable join optimizations in ydb-platform/ydb. Key features delivered include deep-copy memory tracking for Arrow buffers under the memory profiler, enhanced scan fetcher statistics and actor reporting for throughput visibility, and a new configuration to specify the build side in block hash joins. These efforts improve resource usage transparency, data-path performance insights, and deployment flexibility. Demonstrated skills include memory-safe deep copying, metrics instrumentation, and config-driven architecture.
3 Commits • 3 Features
Mar 1, 2026Monthly summary for 2026-03 focusing on delivering memory profiling enhancements, observability improvements, and configurable join optimizations in ydb-platform/ydb. Key features delivered include deep-copy memory tracking for Arrow buffers under the memory profiler, enhanced scan fetcher statistics and actor reporting for throughput visibility, and a new configuration to specify the build side in block hash joins. These efforts improve resource usage transparency, data-path performance insights, and deployment flexibility. Demonstrated skills include memory-safe deep copying, metrics instrumentation, and config-driven architecture.
March 2026
February 2026
12 Commits • 4 Features
Feb 1, 2026February 2026: Strengthened core analytics capabilities and memory resilience in ydb-platform/ydb. Key outcomes include BlockHashJoin core enhancements with type remapping, robust join handling, null bitmap preservation, GraceJoin fallback, and plan/tests; memory management improvements with a no-spiller mode and clear separation of channel vs. compute spilling; expanded benchmarking with new workload transaction modes; and a Scan Fetcher safety enhancement to prevent OOM. These changes improved scalability for larger joins, ensured safer memory behavior under constrained resources, and broadened performance-testing coverage. Demonstrated skills in advanced memory management, performance engineering, test automation, and cross-component integration.
February 2026
12 Commits • 4 Features
Feb 1, 2026February 2026: Strengthened core analytics capabilities and memory resilience in ydb-platform/ydb. Key outcomes include BlockHashJoin core enhancements with type remapping, robust join handling, null bitmap preservation, GraceJoin fallback, and plan/tests; memory management improvements with a no-spiller mode and clear separation of channel vs. compute spilling; expanded benchmarking with new workload transaction modes; and a Scan Fetcher safety enhancement to prevent OOM. These changes improved scalability for larger joins, ensured safer memory behavior under constrained resources, and broadened performance-testing coverage. Demonstrated skills in advanced memory management, performance engineering, test automation, and cross-component integration.
January 2026
1 Commits
Jan 1, 2026January 2026 monthly summary for ydb-platform/ydb: Delivered a critical bug fix in the distributed hash join path, improving correctness and stability. Implemented null bitmap and offset handling improvements in the block hash join converter, added new unit tests, and linked to commit 4aa43b0a5049a5be709ee76381c64e87c0aced49 (Block hash join fix converter for splits (#32765)). This work reduces the risk of incorrect query results in split/distributed execution and enhances reliability for customers relying on distributed hash joins.
1 Commits
Jan 1, 2026January 2026 monthly summary for ydb-platform/ydb: Delivered a critical bug fix in the distributed hash join path, improving correctness and stability. Implemented null bitmap and offset handling improvements in the block hash join converter, added new unit tests, and linked to commit 4aa43b0a5049a5be709ee76381c64e87c0aced49 (Block hash join fix converter for splits (#32765)). This work reduces the risk of incorrect query results in split/distributed execution and enhances reliability for customers relying on distributed hash joins.
January 2026
December 2025
2 Commits • 2 Features
Dec 1, 2025December 2025 Monthly Summary for ydb-platform/ydb: Delivered two targeted performance and maintainability enhancements in the YDB platform. Focused on join performance and asynchronous data handling to improve throughput and reduce operational overhead.
December 2025
2 Commits • 2 Features
Dec 1, 2025December 2025 Monthly Summary for ydb-platform/ydb: Delivered two targeted performance and maintainability enhancements in the YDB platform. Focused on join performance and asynchronous data handling to improve throughput and reduce operational overhead.
November 2025
4 Commits • 2 Features
Nov 1, 2025November 2025 performance and reliability highlights for ydb-platform/ydb. Delivered platform-specific hashing optimizations, refactored hashing code into a dedicated module to improve maintainability and reuse, introduced a scalar layout converter to accelerate data packing/unpacking, and fixed a macOS build issue in hash join. These changes collectively improve hash table throughput, memory efficiency, cross-platform stability, and reduce maintenance friction for platform-specific optimizations.
4 Commits • 2 Features
Nov 1, 2025November 2025 performance and reliability highlights for ydb-platform/ydb. Delivered platform-specific hashing optimizations, refactored hashing code into a dedicated module to improve maintainability and reuse, introduced a scalar layout converter to accelerate data packing/unpacking, and fixed a macOS build issue in hash join. These changes collectively improve hash table throughput, memory efficiency, cross-platform stability, and reduce maintenance friction for platform-specific optimizations.
November 2025
October 2025
3 Commits • 1 Features
Oct 1, 2025For 2025-10, delivered platform-aware SIMD optimizations and stabilized the KqpAgg test suite in ydb-platform/ydb, strengthening performance portability and reliability across environments. Implemented cross-platform SIMD build configuration to disable SIMD on Darwin builds to avoid incompatibilities and enabled AVX2/SSE4.2 optimizations on Linux x86_64, with safe fallbacks for other architectures to maximize hardware-accelerated performance where available. Fixed a heap-use-after-free vulnerability in the KqpAgg test AST access, improving reliability of the testing infrastructure and CI feedback. These changes expand platform coverage, reduce build risk, and accelerate performance-sensitive workloads while maintaining test stability.
October 2025
3 Commits • 1 Features
Oct 1, 2025For 2025-10, delivered platform-aware SIMD optimizations and stabilized the KqpAgg test suite in ydb-platform/ydb, strengthening performance portability and reliability across environments. Implemented cross-platform SIMD build configuration to disable SIMD on Darwin builds to avoid incompatibilities and enabled AVX2/SSE4.2 optimizations on Linux x86_64, with safe fallbacks for other architectures to maximize hardware-accelerated performance where available. Fixed a heap-use-after-free vulnerability in the KqpAgg test AST access, improving reliability of the testing infrastructure and CI feedback. These changes expand platform coverage, reduce build risk, and accelerate performance-sensitive workloads while maintaining test stability.
September 2025
8 Commits • 2 Features
Sep 1, 2025September 2025 monthly summary for ydb-platform/ydb. Key focus on performance, reliability, and build efficiency. Highlights include Hash Join enhancements with SIMD refactor (initial scalar hash join implemented; SIMD library integrated near the join; subsequent revert of SIMD-based pack/unpack to stabilize changes), wakeup callback thread-safety improvements across KQP scan and pure compute actor, and architecture-aware build optimizations (build utilities conditionally compiled for x86_64). In parallel, major reliability improvements include stabilizing logger tests by proper scoping, and disabling problematic ASan test for prototype spilling to address environment-specific issues. Overall, these changes improved query throughput, reduced race conditions, and shortened CI cycles, while maintaining codebase maintainability.
8 Commits • 2 Features
Sep 1, 2025September 2025 monthly summary for ydb-platform/ydb. Key focus on performance, reliability, and build efficiency. Highlights include Hash Join enhancements with SIMD refactor (initial scalar hash join implemented; SIMD library integrated near the join; subsequent revert of SIMD-based pack/unpack to stabilize changes), wakeup callback thread-safety improvements across KQP scan and pure compute actor, and architecture-aware build optimizations (build utilities conditionally compiled for x86_64). In parallel, major reliability improvements include stabilizing logger tests by proper scoping, and disabling problematic ASan test for prototype spilling to address environment-specific issues. Overall, these changes improved query throughput, reduced race conditions, and shortened CI cycles, while maintaining codebase maintainability.
September 2025
August 2025
4 Commits • 1 Features
Aug 1, 2025Month: 2025-08 — Focused on stabilizing the YDB spilling subsystem and documenting the feature. Key outcomes include reliability improvements for large-scale spilling tests, fixes to build issues, and comprehensive user/operator documentation. These work items reduce operational risk in high-volume workloads and demonstrate solid proficiency in C++ code changes, testing, and technical writing.
August 2025
4 Commits • 1 Features
Aug 1, 2025Month: 2025-08 — Focused on stabilizing the YDB spilling subsystem and documenting the feature. Key outcomes include reliability improvements for large-scale spilling tests, fixes to build issues, and comprehensive user/operator documentation. These work items reduce operational risk in high-volume workloads and demonstrate solid proficiency in C++ code changes, testing, and technical writing.
July 2025
3 Commits • 1 Features
Jul 1, 2025July 2025 focused on reliability, correctness, and enabling future query performance in ydb-platform/ydb. Delivered a robust error handling model for channel operations, simplified error semantics across channel storage/compute actors, and completed the initial DqBlockHashJoin integration into the KQP compute path and query compiler, complemented by tests to validate functionality and AST integrity. These changes improve error visibility, reduce special-casing, and establish a solid foundation for reliable distributed query processing.
3 Commits • 1 Features
Jul 1, 2025July 2025 focused on reliability, correctness, and enabling future query performance in ydb-platform/ydb. Delivered a robust error handling model for channel operations, simplified error semantics across channel storage/compute actors, and completed the initial DqBlockHashJoin integration into the KQP compute path and query compiler, complemented by tests to validate functionality and AST integrity. These changes improve error visibility, reduce special-casing, and establish a solid foundation for reliable distributed query processing.
July 2025
June 2025
3 Commits • 2 Features
Jun 1, 2025June 2025 monthly summary for repository ydb-platform/ydb. Focused on delivering testing and performance features within the YDB query processing pipeline, alongside establishing foundational support for block-based joins.
June 2025
3 Commits • 2 Features
Jun 1, 2025June 2025 monthly summary for repository ydb-platform/ydb. Focused on delivering testing and performance features within the YDB query processing pipeline, alongside establishing foundational support for block-based joins.
Activity
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Quality Metrics
Correctness86.6%
Maintainability85.2%
Architecture83.4%
Performance80.6%
AI Usage22.8%
Skills & Technologies
Programming Languages
C++MarkdownPython
Technical Skills
Actor ModelAlgorithm DesignAlgorithm ImplementationAlgorithm OptimizationBackend DevelopmentBenchmarkingBug FixingBuild SystemBuild System ConfigurationBuild SystemsC++C++ DevelopmentC++ developmentC++ programmingCode Organization
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