HazyResearch/ThunderKittens
Oct 2024 – Jan 2026
12 Months active
Languages Used
C++CUDAPythonMakefileMarkdownJavaScript
Technical Skills
Assembly languageC++CUDACUDA ProgrammingCUDA programmingCode Refactoring
Benjamin Spector
PROFILE
Benjamin Spector
Benjamin Spector developed core GPU computing infrastructure for the HazyResearch/ThunderKittens repository, focusing on scalable machine learning workloads and high-performance kernel execution. Over twelve months, he engineered features such as modular CUDA kernels, multi-GPU support, and a virtual machine subsystem, emphasizing maintainability and cross-architecture compatibility. His technical approach combined C++, CUDA, and template metaprogramming to streamline memory management, enable efficient matrix operations, and introduce robust synchronization primitives. By integrating compile-time validation, asynchronous operations, and detailed benchmarking, Benjamin improved reliability and developer velocity. His work addressed both performance and correctness, laying a strong foundation for future extensibility and cross-platform deployment.
Overall Statistics
Feature vs Bugs
68%Features
Repository Contributions
193Total
Bugs
40
Commits
193
Features
84
Lines of code
60,651
Activity Months12
Your Network
23 people
Work History
January 2026
1 Commits • 1 Features
Jan 1, 2026January 2026 monthly summary for HazyResearch/ThunderKittens: Delivered a feature that enhances Pyutils binding for struct variants with compile-time validation, improving safety and reducing integration errors. This work focuses on robust type bindings, early error detection, and maintainable code paths. No major bugs fixed this month; the team concentrated on architecture stabilization and code quality. Overall impact: stronger foundation for scalable struct variant usage and safer cross-module bindings, enabling faster development cycles and fewer runtime issues. Technologies/skills demonstrated: Python bindings, compile-time checks, type systems, maintainability through commit-driven development.
1 Commits • 1 Features
Jan 1, 2026January 2026 monthly summary for HazyResearch/ThunderKittens: Delivered a feature that enhances Pyutils binding for struct variants with compile-time validation, improving safety and reducing integration errors. This work focuses on robust type bindings, early error detection, and maintainable code paths. No major bugs fixed this month; the team concentrated on architecture stabilization and code quality. Overall impact: stronger foundation for scalable struct variant usage and safer cross-module bindings, enabling faster development cycles and fewer runtime issues. Technologies/skills demonstrated: Python bindings, compile-time checks, type systems, maintainability through commit-driven development.
January 2026
September 2025
2 Commits • 1 Features
Sep 1, 2025Month 2025-09 — HazyResearch/ThunderKittens: Focused on codebase consistency and future-ready optimizations through a targeted refactor. Implemented a codebase-wide adoption of the kittens::warp namespace for common operations in matmul examples and the linear attention kernels, across B200, FP8, and H100 compute paths. No major bugs fixed this period. Impact includes improved maintainability, standardized cross-arch patterns, and a solid foundation for forthcoming performance tuning.
September 2025
2 Commits • 1 Features
Sep 1, 2025Month 2025-09 — HazyResearch/ThunderKittens: Focused on codebase consistency and future-ready optimizations through a targeted refactor. Implemented a codebase-wide adoption of the kittens::warp namespace for common operations in matmul examples and the linear attention kernels, across B200, FP8, and H100 compute paths. No major bugs fixed this period. Impact includes improved maintainability, standardized cross-arch patterns, and a solid foundation for forthcoming performance tuning.
August 2025
2 Commits • 2 Features
Aug 1, 20252025-08 monthly summary for HazyResearch/ThunderKittens focusing on multi-GPU readiness, API consistency, and project clarity. Implemented key CUDA kernel API reordering to move dev_idx to the end for consistency across memory ops and enabled a multi-GPU test flag in the Makefile. Addressed a pgls-related bug within the same patch set and ensured cross-GPU validation now has a dedicated test flag. Updated the README to reflect major developments: large branch merge, significant code refactor, explicit warp scope requirement, and TK 3.0 roadmap notes to guide future contributions. These changes strengthen reliability for multi-GPU workloads, improve onboarding, and set the direction for TK 3.0.
2 Commits • 2 Features
Aug 1, 20252025-08 monthly summary for HazyResearch/ThunderKittens focusing on multi-GPU readiness, API consistency, and project clarity. Implemented key CUDA kernel API reordering to move dev_idx to the end for consistency across memory ops and enabled a multi-GPU test flag in the Makefile. Addressed a pgls-related bug within the same patch set and ensured cross-GPU validation now has a dedicated test flag. Updated the README to reflect major developments: large branch merge, significant code refactor, explicit warp scope requirement, and TK 3.0 roadmap notes to guide future contributions. These changes strengthen reliability for multi-GPU workloads, improve onboarding, and set the direction for TK 3.0.
August 2025
July 2025
6 Commits • 4 Features
Jul 1, 2025July 2025 — ThunderKittens: Delivered CUDA-oriented tooling and reliability improvements across features and bug fixes, enhancing performance, stability, and developer experience. Key outcomes include CUDA Vector Load/Store Utilities enabling efficient vector ops; hasnan for robust NaN detection across tiles/vectors using warp-level ballots; asynchronous CUDA stream support in KittensClub; warpgroup subtile access bug fix; improved PGL tensor size validation error messages for faster debugging; all changes backed by unit tests and targeted reviews, translating to measurable developer time savings and fewer runtime anomalies.
July 2025
6 Commits • 4 Features
Jul 1, 2025July 2025 — ThunderKittens: Delivered CUDA-oriented tooling and reliability improvements across features and bug fixes, enhancing performance, stability, and developer experience. Key outcomes include CUDA Vector Load/Store Utilities enabling efficient vector ops; hasnan for robust NaN detection across tiles/vectors using warp-level ballots; asynchronous CUDA stream support in KittensClub; warpgroup subtile access bug fix; improved PGL tensor size validation error messages for faster debugging; all changes backed by unit tests and targeted reviews, translating to measurable developer time savings and fewer runtime anomalies.
June 2025
2 Commits • 2 Features
Jun 1, 2025June 2025 performance summary for HazyResearch/ThunderKittens focused on delivering scalable GPU capabilities and improving synchronization control. Two core features were completed, with an emphasis on modularity, maintainability, and future-proofed multi-GPU support.
2 Commits • 2 Features
Jun 1, 2025June 2025 performance summary for HazyResearch/ThunderKittens focused on delivering scalable GPU capabilities and improving synchronization control. Two core features were completed, with an emphasis on modularity, maintainability, and future-proofed multi-GPU support.
June 2025
May 2025
8 Commits • 3 Features
May 1, 2025May 2025 monthly performance summary for ThunderKittens: Delivered core platform enhancements enabling higher-performance VM execution and ML workloads. Key work included an intra-pipelined VM memory management refactor to streamline page arrivals/departures, expanding memory-management efficiency within the VM. Implemented hardware-architecture support and performance instrumentation with hardware-specific timing management and cross-arch instrumentation for Blackwell and Hopper, including NoOp structure and VM kernel timing improvements. Introduced an MLP micro-architecture with pipelined matrix-vector operations (Up/Down kernels) and configured pipeline stages, augmented by timing instrumentation for ML pipelines. Also completed targeted stability and maintainability refinements to support cross-architecture plots (Hopper/MLA) and ensured build consistency across refactors.
May 2025
8 Commits • 3 Features
May 1, 2025May 2025 monthly performance summary for ThunderKittens: Delivered core platform enhancements enabling higher-performance VM execution and ML workloads. Key work included an intra-pipelined VM memory management refactor to streamline page arrivals/departures, expanding memory-management efficiency within the VM. Implemented hardware-architecture support and performance instrumentation with hardware-specific timing management and cross-arch instrumentation for Blackwell and Hopper, including NoOp structure and VM kernel timing improvements. Introduced an MLP micro-architecture with pipelined matrix-vector operations (Up/Down kernels) and configured pipeline stages, augmented by timing instrumentation for ML pipelines. Also completed targeted stability and maintainability refinements to support cross-architecture plots (Hopper/MLA) and ensured build consistency across refactors.
April 2025
29 Commits • 13 Features
Apr 1, 2025April 2025, ThunderKittens: Delivered foundational VM and computational kernels with strong emphasis on reliability, portability, and performance potential. Key features include matmul support and optimization; VM core refactor; dynamic semaphore initialization; KVM hello world; checkpointing; 2600 compatibility; and matvec/test enhancements. Fixed paging and instruction boundary issues to improve test stability and build progress. This work lays the groundwork for scalable execution, cross-platform compatibility, and improved observability.
29 Commits • 13 Features
Apr 1, 2025April 2025, ThunderKittens: Delivered foundational VM and computational kernels with strong emphasis on reliability, portability, and performance potential. Key features include matmul support and optimization; VM core refactor; dynamic semaphore initialization; KVM hello world; checkpointing; 2600 compatibility; and matvec/test enhancements. Fixed paging and instruction boundary issues to improve test stability and build progress. This work lays the groundwork for scalable execution, cross-platform compatibility, and improved observability.
April 2025
March 2025
58 Commits • 19 Features
Mar 1, 2025March 2025 — ThunderKittens (HazyResearch) Focus: reliability, correctness, and performance across scheduling, interpreter, and tooling. Key deliverables: - Scheduler Infrastructure and Optimizations: new infra, optimization, and edge-case processor assignment; correctness improvements in 0-reduction cases. - Test Infrastructure Enhancements: more reliable test infra and expanded coverage. - Core interpreter scaffolding and API stabilization: established core scaffolding, ongoing refactor with optional runtime checks, tests aligned. - Memory refactor and tests stabilization: refactored memory subsystem with all memory tests passing and group memory tests passing. - FP8 TS MMA support and related kernel work: added FP8 tensor-slicing MMA support and supporting kernels. Results and impact: - Improved numerical correctness (notably matmul fixes) and stability (tests back to passing, pre-merge readiness), with performance tuning seen in MHA/hopper pathways and timing infra enabling betterBenchmarking. - Stronger release readiness and lower risk due to enhanced test coverage and API stabilization. Technologies/skills demonstrated: - Scheduling system design and optimization, GPU-oriented kernel work, test automation, interpreter refactoring, API stabilization, and cross-cutting performance engineering.
March 2025
58 Commits • 19 Features
Mar 1, 2025March 2025 — ThunderKittens (HazyResearch) Focus: reliability, correctness, and performance across scheduling, interpreter, and tooling. Key deliverables: - Scheduler Infrastructure and Optimizations: new infra, optimization, and edge-case processor assignment; correctness improvements in 0-reduction cases. - Test Infrastructure Enhancements: more reliable test infra and expanded coverage. - Core interpreter scaffolding and API stabilization: established core scaffolding, ongoing refactor with optional runtime checks, tests aligned. - Memory refactor and tests stabilization: refactored memory subsystem with all memory tests passing and group memory tests passing. - FP8 TS MMA support and related kernel work: added FP8 tensor-slicing MMA support and supporting kernels. Results and impact: - Improved numerical correctness (notably matmul fixes) and stability (tests back to passing, pre-merge readiness), with performance tuning seen in MHA/hopper pathways and timing infra enabling betterBenchmarking. - Stronger release readiness and lower risk due to enhanced test coverage and API stabilization. Technologies/skills demonstrated: - Scheduling system design and optimization, GPU-oriented kernel work, test automation, interpreter refactoring, API stabilization, and cross-cutting performance engineering.
February 2025
29 Commits • 12 Features
Feb 1, 2025February 2025 — ThunderKittens monthly summary for HazyResearch. Focused on stabilizing the codebase, enabling performance improvements, and advancing experimentation with fault-tolerance features and scripting capabilities. Key efforts spanned build reliability, runtime safeguards, and early-stage demo readiness. Key features delivered: - Include path improvements: minor header/search path enhancements to speed up compilation and reduce build failures (commit: bbd75abf84ca0c7cab8276622ca5154d88f563d9). - Template updates for Blackwell; MLA kernel demo now working: lcf and lcsf templates updated; demo MLA kernel appears functional (commit: 0bc94f3f6dfed8b32b9416f1fd01f28a2ed8b192). - Interpreter prototype: introduced an experimental scripting/command-execution prototype to explore automation in workflows (commit: ba4c1e1d1c7d110a11083b2198d06f6e7810929a). - Checkpointing features: added checkpointing before sleep to preserve state and a final checkpoint step to solidify workflows (commits: a46eb045281537b224b745c9dad848a0cd152259; e8366eff21f8878b918a9f9a69c05192f8f17a77). - Performance benchmarking suite: introduced a suite of performance benchmarks to establish baselines and quantify improvements (commit: 6c10b1dcfe0b6281cdd848c85d9e6d13abad1fb9). Major bugs fixed: - Merge conflict fix: resolved an unwanted batch merge issue to stabilize integration (commit: 4d3acb50ba67aab9307232eb803fc0807ef95161). - MQA parallel reduction bug fix: enabled and stabilized parallel reduction in MQA (commit: 1f87372bd014401db568e05515b666e3bff2c2a3). - Reduction spill fix: addressed mostly resolved spills to ensure correctness in reductions (commit: 958fe0f6284fdd2f84fdfd7d905c3ba98b9182f1). - Typename handling bug: fixed issues related to typename usage in codegen/parsing (commit: f4299243633c0574744c26fc580a5ea89ce55279). - Semaphore fixes: cleaned up semaphore usage and fixed related issues (commits: 220feed9a805cca533346020110838d544b3fd07; 6d78942659e295d39e353db25df153915a0e3f89). - Miscellaneous fixes: various small fixes and cleanup across the codebase (commits: c045888a29878ebb83b3a86845fc57e135d404e5; 1a8d5a4493609e2f0c360a51fb4c2177ea3ad1a1; ce0f45ce9562a5d23625262c89ce63be8cdccc8f; 7e2d6e8ef747b89ec391013d0e87891403799e36; 25d1a74395c0aff9224fbb99e341b9f8febb6903). - Placeholder/garbage and empty commits: identified and deprioritized as non-functional noise (commits: a155246fd2623348c412df0a7f13aea33c1b67a9; bdd0d977c9c51ee1c345ff359f2d48820ae32502). Overall impact and accomplishments: - Increased build stability and developer velocity through include-path hardening and merge conflict resolution. - Introduced fault-tolerance and state-preservation capabilities with checkpointing, enabling safer long-running runs. - Established a performance measurement baseline via the benchmarking suite and fixed critical paths in MQA parallel reduction. - Advanced exploratory capabilities with an interpreter prototype and a demonstrable MLA kernel workflow on Blackwell templates, illustrating concrete progress toward future features. - Continued code quality improvements through targeted fixes (reduction correctness, typename handling, semaphores, visualizer tweaks). Technologies and skills demonstrated: - C/C++ build systems and template handling, include-path management, and build reliability engineering. - Debugging and root-cause analysis for concurrency (semaphores) and numerical correctness (reductions, spills). - Performance optimization and measurement (parallel reductions, benchmarks). - Experimental UI/UX and scripting exploration (interpreter prototype, template readability improvements). - State management and fault-tolerance design (checkpointing).
29 Commits • 12 Features
Feb 1, 2025February 2025 — ThunderKittens monthly summary for HazyResearch. Focused on stabilizing the codebase, enabling performance improvements, and advancing experimentation with fault-tolerance features and scripting capabilities. Key efforts spanned build reliability, runtime safeguards, and early-stage demo readiness. Key features delivered: - Include path improvements: minor header/search path enhancements to speed up compilation and reduce build failures (commit: bbd75abf84ca0c7cab8276622ca5154d88f563d9). - Template updates for Blackwell; MLA kernel demo now working: lcf and lcsf templates updated; demo MLA kernel appears functional (commit: 0bc94f3f6dfed8b32b9416f1fd01f28a2ed8b192). - Interpreter prototype: introduced an experimental scripting/command-execution prototype to explore automation in workflows (commit: ba4c1e1d1c7d110a11083b2198d06f6e7810929a). - Checkpointing features: added checkpointing before sleep to preserve state and a final checkpoint step to solidify workflows (commits: a46eb045281537b224b745c9dad848a0cd152259; e8366eff21f8878b918a9f9a69c05192f8f17a77). - Performance benchmarking suite: introduced a suite of performance benchmarks to establish baselines and quantify improvements (commit: 6c10b1dcfe0b6281cdd848c85d9e6d13abad1fb9). Major bugs fixed: - Merge conflict fix: resolved an unwanted batch merge issue to stabilize integration (commit: 4d3acb50ba67aab9307232eb803fc0807ef95161). - MQA parallel reduction bug fix: enabled and stabilized parallel reduction in MQA (commit: 1f87372bd014401db568e05515b666e3bff2c2a3). - Reduction spill fix: addressed mostly resolved spills to ensure correctness in reductions (commit: 958fe0f6284fdd2f84fdfd7d905c3ba98b9182f1). - Typename handling bug: fixed issues related to typename usage in codegen/parsing (commit: f4299243633c0574744c26fc580a5ea89ce55279). - Semaphore fixes: cleaned up semaphore usage and fixed related issues (commits: 220feed9a805cca533346020110838d544b3fd07; 6d78942659e295d39e353db25df153915a0e3f89). - Miscellaneous fixes: various small fixes and cleanup across the codebase (commits: c045888a29878ebb83b3a86845fc57e135d404e5; 1a8d5a4493609e2f0c360a51fb4c2177ea3ad1a1; ce0f45ce9562a5d23625262c89ce63be8cdccc8f; 7e2d6e8ef747b89ec391013d0e87891403799e36; 25d1a74395c0aff9224fbb99e341b9f8febb6903). - Placeholder/garbage and empty commits: identified and deprioritized as non-functional noise (commits: a155246fd2623348c412df0a7f13aea33c1b67a9; bdd0d977c9c51ee1c345ff359f2d48820ae32502). Overall impact and accomplishments: - Increased build stability and developer velocity through include-path hardening and merge conflict resolution. - Introduced fault-tolerance and state-preservation capabilities with checkpointing, enabling safer long-running runs. - Established a performance measurement baseline via the benchmarking suite and fixed critical paths in MQA parallel reduction. - Advanced exploratory capabilities with an interpreter prototype and a demonstrable MLA kernel workflow on Blackwell templates, illustrating concrete progress toward future features. - Continued code quality improvements through targeted fixes (reduction correctness, typename handling, semaphores, visualizer tweaks). Technologies and skills demonstrated: - C/C++ build systems and template handling, include-path management, and build reliability engineering. - Debugging and root-cause analysis for concurrency (semaphores) and numerical correctness (reductions, spills). - Performance optimization and measurement (parallel reductions, benchmarks). - Experimental UI/UX and scripting exploration (interpreter prototype, template readability improvements). - State management and fault-tolerance design (checkpointing).
February 2025
January 2025
28 Commits • 9 Features
Jan 1, 2025January 2025 performance summary for HazyResearch/ThunderKittens: Delivered substantial operator overload enhancements with attention and MMA support, enabling more expressive and efficient model execution. Achieved a real-world performance milestone of 877.5 TFLOPs on targeted kernels, with matmul improvements including faster 2-CTA checkpointing and a clear path toward the 1250 TFLOPs goal. Aligned platform nomenclature to actual hardware (B200s) and began Blackwell refactoring groundwork to support future platform upgrades. Implemented extensive kernel cleanups, convention fixes, and safety-oriented incremental changes to reduce risk and improve maintainability. Strengthened core utilities (util.cuh, tma.cuh, mma.cuh, tmem.cuh) to improve consistency across components. These efforts deliver business value by enabling higher-throughput workloads, improving stability, and accelerating platform readiness for next-gen hardware.
January 2025
28 Commits • 9 Features
Jan 1, 2025January 2025 performance summary for HazyResearch/ThunderKittens: Delivered substantial operator overload enhancements with attention and MMA support, enabling more expressive and efficient model execution. Achieved a real-world performance milestone of 877.5 TFLOPs on targeted kernels, with matmul improvements including faster 2-CTA checkpointing and a clear path toward the 1250 TFLOPs goal. Aligned platform nomenclature to actual hardware (B200s) and began Blackwell refactoring groundwork to support future platform upgrades. Implemented extensive kernel cleanups, convention fixes, and safety-oriented incremental changes to reduce risk and improve maintainability. Strengthened core utilities (util.cuh, tma.cuh, mma.cuh, tmem.cuh) to improve consistency across components. These efforts deliver business value by enabling higher-throughput workloads, improving stability, and accelerating platform readiness for next-gen hardware.
November 2024
22 Commits • 16 Features
Nov 1, 2024Month: 2024-11. Focused feature delivery and stabilization across ThunderKittens to enable broader workloads on newer hardware, improve data path reliability, and reduce padding-related overhead. Key progress includes dimension support, axis loading, and robust build/test improvements, driving measurable business value in performance, hardware utilization, and deployment reliability.
22 Commits • 16 Features
Nov 1, 2024Month: 2024-11. Focused feature delivery and stabilization across ThunderKittens to enable broader workloads on newer hardware, improve data path reliability, and reduce padding-related overhead. Key progress includes dimension support, axis loading, and robust build/test improvements, driving measurable business value in performance, hardware utilization, and deployment reliability.
November 2024
October 2024
6 Commits • 2 Features
Oct 1, 2024October 2024 monthly summary for HazyResearch/ThunderKittens. Focused on performance optimizations for CUDA kernels, memory management robustness, and code cleanup to improve speed, reliability, and maintainability. Delivered two major features and three critical bug fixes, with concrete commit references enabling reproducibility and auditability.
October 2024
6 Commits • 2 Features
Oct 1, 2024October 2024 monthly summary for HazyResearch/ThunderKittens. Focused on performance optimizations for CUDA kernels, memory management robustness, and code cleanup to improve speed, reliability, and maintainability. Delivered two major features and three critical bug fixes, with concrete commit references enabling reproducibility and auditability.
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Quality Metrics
Correctness85.0%
Maintainability82.8%
Architecture82.8%
Performance80.6%
AI Usage20.8%
Skills & Technologies
Programming Languages
C++CUDAJavaScriptMakefileMarkdownPython
Technical Skills
Algorithm DesignAlgorithm RefinementAssembly languageAsynchronous OperationsAsynchronous ProgrammingAsynchronous operationsAttention MechanismsBackend DevelopmentBenchmarkingBoilerplate Code ReductionBokehBuild SystemsBuild system configurationC++C++ Development
Repositories Contributed To
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