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xutizhou

PROFILE

Xutizhou

Over seven months, contributed to advanced GPU-accelerated deep learning infrastructure across multiple sgLang and FlashInfer repositories. Focused on optimizing Mixture-of-Experts routing, kernel fusion, and memory safety, the work included refactoring Triton and CUDA kernels, integrating FP8 quantization, and implementing waterfill-based load balancing for distributed systems. Addressed memory access bugs and improved inference throughput by fusing kernels and reducing CPU-GPU overhead. Enhanced model stability and routing efficiency through robust expert dispatch mechanisms and targeted unit testing. Leveraged C++, Python, and PyTorch to deliver scalable, production-ready features, demonstrating depth in low-level optimization, distributed systems, and collaborative cross-repository development.

Overall Statistics

Feature vs Bugs

73%Features

Repository Contributions

13Total
Bugs
3
Commits
13
Features
8
Lines of code
3,975
Activity Months7

Work History

May 2026

4 Commits • 1 Features

May 1, 2026

May 2026: Delivered DeepEP Waterfill-based routing optimization and EPLB mapping fixes in the sgLang project, with targeted test coverage to ensure correctness and stability. The work focused on consolidating waterfill load balancing for shared dispatch, enabling Waterfill support in TopK/HashTopK, and refining shared expert fusion to reduce redundant computation, improving routing efficiency and latency. Additionally, EPLB mapping correctness was addressed with a new test validating biased TopK mapping. Overall, these changes improve performance, reliability, and maintainability of the dispatch and routing subsystem.

April 2026

2 Commits • 1 Features

Apr 1, 2026

2026-04 Monthly Summary Key features delivered - bytedance-iaas/sglang: Mixture of Experts: Fuse shared experts into MoE dispatch under DeepEP to improve routing efficiency and management in distributed settings. Commit: 57ffc55fb647bfc241d8c4766b846f4243b9c81d (feat: [1/2] [DeepEP] Fuse shared expert into MoE dispatch under EP). Co-authored by Claude Sonnet 4.6 and AichenF. Major bugs fixed - sgl-project/sglang: Robust EPLB Dispatch for Shared Experts Fusion. Fixed out-of-bounds in EPLB dispatch when shared experts fusion is enabled; restrict remapping to routed expert columns to prevent crashes and incorrect routing, improving model stability and reliability. Commit: 3cb3f7c01814c90f3f4aacde83f6f2cfcd20ed35 (fix: EPLB dispatch OOB under DeepEP). Overall impact and accomplishments - Stabilized MoE routing under DeepEP across distributed settings; enables safer experimentation with shared-experts at scale; improved routing efficiency, reliability, and maintainability for MoE features. Technologies/skills demonstrated - Mixture of Experts (MoE), DeepEP, EPLB; distributed systems thinking; performance and stability focus; collaborative development and code review; cross-repo feature integration.

March 2026

2 Commits • 2 Features

Mar 1, 2026

March 2026: Two high-impact feature deliveries across sgLang and FlashInfer that improved inference performance and memory efficiency for modern GPU workloads. Implemented K-last SSM layout support for GDN prefill/decode, and introduced pool-indexed (zero-copy) state access for the GDN decode kernel, enabling efficient integration with SGLang's state pool. These changes reduce latency, boost throughput for linear-attention models, and strengthen production readiness for SGLang+FlashInfer deployments on Hopper-era GPUs.

February 2026

2 Commits • 2 Features

Feb 1, 2026

February 2026 performance snapshot focused on low-level performance optimizations and kernel fusion to boost inference throughput and scalability in FlashInfer and SGLang. The work emphasizes reducing CPU-GPU overhead and consolidating kernel launches for critical paths.

June 2025

1 Commits • 1 Features

Jun 1, 2025

June 2025 monthly summary for kvcache-ai/sglang: Delivered FP8-optimized DeepGEMM integration into the EPMoE path, including new Triton kernels for data reordering and computation and a forward-pass refactor to streamline FP8 data paths. This work establishes a robust FP8 data-path foundation and sets the stage for targeted performance tuning; no major bugs fixed this period.

May 2025

1 Commits

May 1, 2025

May 2025 monthly summary for kvcache-ai/sglang: Major bug fix to MoE forward pass memory safety and correctness, addressing illegal memory access and preventing potential out-of-bounds errors. The fix enhances stability for expert-parallel MoE forwards under large-scale workloads and improves reliability of production deployments.

March 2025

1 Commits • 1 Features

Mar 1, 2025

March 2025 monthly summary focused on performance optimization for DeepEP Mixture-of-Experts in kvcache-ai/sglang. Delivered a permute kernel optimization by refactoring Triton kernels and adjusting data flow for expert processing, optimizing permutation and un-permutation steps. This work enhances throughput and reduces latency in Mixture-of-Experts routing and data distribution.

Activity

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Quality Metrics

Correctness92.4%
Maintainability80.0%
Architecture86.2%
Performance87.6%
AI Usage38.4%

Skills & Technologies

Programming Languages

C++Python

Technical Skills

CUDAData ProcessingDeep LearningDistributed SystemsFP8 QuantizationGPU ComputingGPU ProgrammingGPU programmingLoad BalancingLow-level OptimizationMachine LearningMixture of Experts (MoE)Model OptimizationOptimizationPerformance optimization

Repositories Contributed To

6 repos

Overview of all repositories you've contributed to across your timeline

kvcache-ai/sglang

Mar 2025 Feb 2026
4 Months active

Languages Used

C++Python

Technical Skills

Deep LearningDistributed SystemsGPU ProgrammingOptimizationPyTorchTriton

yhyang201/sglang

May 2026 May 2026
1 Month active

Languages Used

Python

Technical Skills

Data ProcessingDeep LearningDistributed SystemsLoad BalancingMachine LearningModel Optimization

flashinfer-ai/flashinfer

Feb 2026 Mar 2026
2 Months active

Languages Used

C++Python

Technical Skills

CUDAGPU programmingPerformance optimizationDeep LearningGPU ProgrammingMachine Learning

ping1jing2/sglang

Mar 2026 Mar 2026
1 Month active

Languages Used

Python

Technical Skills

CUDAGPU programmingdeep learningmachine learning

bytedance-iaas/sglang

Apr 2026 Apr 2026
1 Month active

Languages Used

Python

Technical Skills

Deep LearningDistributed SystemsMachine LearningPyTorch

sgl-project/sglang

Apr 2026 Apr 2026
1 Month active

Languages Used

Python

Technical Skills

Deep LearningMachine LearningPython