About H:
H exists to push the boundaries of superintelligence with agentic AI. By automating complex, multi-step tasks typically performed by humans, AI agents will help unlock full human potential.

H is hiring the world’s best AI talent, seeking those who are dedicated as much to building safely and responsibly as to advancing disruptive agentic capabilities. We promote a mindset of openness, learning, and collaboration, where everyone has something to contribute.

About the Team: The Inference team develops and enhances the inference stack for serving H-models that power our agent technology. The team focuses on optimizing hardware utilization to reach high throughput, low latency and cost efficiency in order to deliver a seamless user experience.

Key Responsibilities:

• Develop scalable, low-latency and cost effective inference pipelines

• Optimize model performance: memory usage, throughput, and latency, using advanced techniques like distributed computing, model compression, quantization and caching mechanisms

• Develop specialized GPU kernels for performance-critical tasks like attention mechanisms, matrix multiplications, etc.

• Collaborate with H research teams on model architectures to enhance efficiency during inference

• Review state-of-the-art papers to improve memory usage, throughput and latency (Flash attention, Paged Attention, Continuous batching, etc.)

• Prioritize and implement state-of-the-art inference techniques

Requirements:

• Technical skills:

  • MS or PhD in Computer Science, Machine Learning or related fields

  • Proficient in at least one of the following programming languages: Python, Rust or C/C++

  • Experience in GPU programming such as CUDA, Open AI Triton, Metal, etc.

  • Experience in model compression and quantization techniques

• Soft skills

  • Collaborative mindset, thriving in dynamic, multidisciplinary teams

  • Strong communication and presentation skills

  • Eager to explore new challenges

• Bonuses:

  • Experience with LLM serving frameworks such as vLLM, TensorRT-LLM, SGLang, llama.cpp, etc.

  • Experience with CUDA kernel programming and NCCL

  • Experience in deep learning inference framework (Pytorch/execuTorch, ONNX Runtime, GGML, etc.)

Location:

• Paris or London.

• This role is hybrid, and you are expected to be in the office 3 days a week on average.

• The final decision for this will lie with the hiring manager for each individual role

What We Offer:

• Join the exciting journey of shaping the future of AI, and be part of the early days of one of the hottest AI startups

• Collaborate with a fun, dynamic and multicultural team, working alongside world-class AI talent in a highly collaborative environment

• Enjoy a competitive salary

• Unlock opportunities for professional growth, continuous learning, and career development

If you want to change the status quo in AI, join us.