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Luca H.
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Luca H.

LLM/VLM Engineer | Distributed Training, vLLM & CUDA Optimization

I help teams train, optimize, and deploy LLMs and multimodal models at production scale. I'm a Staff Machine Learning Engineer specializing in distributed LLM/VLM training, RL post-training, and GPU-optimized inference. I work across the full ML stack—from data pipelines and model architecture to multi-node training, evaluation, vLLM/TensorRT deployment, and performance profiling. Selected results: • Scaled distributed VLM training to 16 nodes / 128 GPUs through NCCL and eRDMA optimization • Increased average GPU utilization from approximately 30% to 85% and improved end-to-end vLLM inference throughput by 4.5x • Reduced multimodal video preprocessing time by more than 99% • Built a 32-GPU GRPO post-training pipeline that improved recall on key long-tail categories by up to 38% • Delivered a C++/CUDA TensorRT inference stack achieving 5 ms latency on an NVIDIA RTX 4090 • Contributed merged upstream improvements to LLaMA-Factory and LinkedIn's Liger Kernel I can help with: • LLM/VLM fine-tuning, SFT, LoRA/QLoRA, GRPO, and evaluation • Multi-node distributed training and GPU utilization optimization • vLLM, SGLang, and TensorRT inference pipelines • CUDA/Triton kernel integration, profiling, quantization, and latency optimization • Multimodal, video, computer-vision, and 3D AI systems Core stack: PyTorch, Hugging Face Transformers, LLaMA-Factory, DeepSpeed, verl, vLLM, TensorRT, CUDA, Triton, C++, and Python.

🇨🇳Shanghai, China$65/hr100% JSSSince Oct 2025

Earnings and projects

MRR
$118

Last 6 months ÷ 6

World#130,522 / 412k
🇨🇳Country#757 / 2,007
Revenue, last 30 days
$0

Last 6 months: $706

Total earnings
$7.3k

Billed in all: $7.9k

World#222,805 / 412k
🇨🇳Country#951 / 2,007
Per project
$7.3k

$706 in the last 6 months

World#23,217 / 412k
🇨🇳Country#63 / 2,007
Projects, last 6 months
1

Across 2 contracts

0% fixed100% hourly
World#128,092 / 412k
🇨🇳Country#730 / 2,007
Projects in all
1

Across 2 contracts

0% fixed100% hourly
World#360,671 / 412k
🇨🇳Country#1,713 / 2,007

Earnings, last 30 days

$7.9kNothing earned in the last 30 daysBilled in all, before Upwork's fee · drag across the chart to see what was earned in any stretch
$7.7k$7.8k$7.9k$8.0kOct 8Oct 23Nov 7

Skill rankings: Top 22% in CUDA

Ranked by MRR among everyone on Upwork with the skill.

  1. #16TensorRT39 freelancers · 🇨🇳 #1Top 41%
  2. #35CUDA161 freelancers · 🇨🇳 #1Top 22%
  3. #56Reinforcement Learning214 freelancers · 🇨🇳 #1Top 26%
  4. #70Multimodal Large Language Model177 freelancers · 🇨🇳 #2Top 40%
  5. #88Hugging Face300 freelancers · 🇨🇳 #3Top 29%
  6. #348Machine Learning Model1,169 freelancers · 🇨🇳 #7Top 30%
  7. #412PyTorch1,585 freelancers · 🇨🇳 #8Top 26%
  8. #720Deep Learning2,743 freelancers · 🇨🇳 #11Top 26%