Research Scientist Intern (PhD) - Model Team - London

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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 Agent team defines new learning algorithms and agent paradigms to push the frontiers of agentic systems. We build upon foundation models and reinforcement learning to develop new approaches to train artificial general agents and work closely with the LLM/VLM and Safety teams to explore new directions. This is a heavily engineering-focused role embedded within the research team. You will be responsible for defining the architecture and building the robust, scalable systems that underpin our research efforts. Your work will translate cutting-edge research concepts into high-performance, production-quality platforms, enabling the next generation of agentic AI. Key Responsibilities: * Research & Leadership: Design and develop new agents, proposing new research directions, e.g., combining state-of-the-art RL with foundation models (LLMs/VLMs). * Algorithm & Systems Design: Design, implement, and scale complex, high-performance systems for training large-scale agents. This includes both the foundational infrastructure and the novel algorithms, reward models, and sophisticated training environments. * Research-to-Production: Collaborate closely with researchers and engineers to implement, test, and productionize new agent logics, learning algorithms, and system architectures. * Evaluation & Reliability: Create, manage, and scale massive benchmarks and evaluation systems to rigorously track agent capabilities. You will own system reliability, scalability, and observability for our entire research infrastructure. * Mentorship & Standards: Mentor and guide other engineers and researchers on the team, fostering technical excellence. You will establish and enforce engineering standards, tooling, and best practices for both code and research design. * Innovation: Conduct thorough code and design reviews, champion technical innovation, and proactively address technical debt to accelerate the R&D lifecycle. Requirements: * Technical Skills: * Senior Experience: Previous demonstrable role(s) as a Staff, Principal, or Senior Engineer (or equivalent Research Scientist) in a Frontier AI Lab with a proven track record of leading complex, end-to-end AI/ML projects from conception to production. * Education / Publication: Preferably PhD (or equivalent research experience) in Machine Learning, Computer Science, or a related field, preferably with a strong publication record (e.g., NeurIPS, ICML, ICLR) in Computer Science. * Core Expertise: Deep theoretical and practical expertise in Agentic AI and proven experience building, scaling, and shipping solutions involving foundation models (LLMs/VLMs). * Soft Skills: * Collaborative: Enjoys collaboration and thrives in a teamwork-oriented, fast-paced research environment. * High-Impact Communicator: Possesses impactful communication skills, with the ability to bridge the gap between research and engineering and articulate complex ideas clearly. * Mission-Driven: Genuinely eager to explore and solve the new engineering and research challenges at the frontier of agentic AI. * Bonus Skills: * Practical experience applying Reinforcement Learning to systems built on Large Language Models (LLMs). * Experience with distributed systems or cloud computing, preferably in AWS. * Familiarity with building complex simulation environments for agent training. * Experience with LLM training or fine-tuning. * Experience developing large-scale evaluation and benchmarking systems for AI models. * Experience in an agentic framework (e.g., LangChain, AutoGen, CrewAI, OpenAI SDK). * Expertise in system architecture, instrumentation, observability, and monitoring for complex, high-performance systems. Location: * Paris or London. * This role is hybrid, and you are expected to be in the office 3 days a week on average. * Please expect some travel between offices on a reasonable cadence (e.g., every 4-6 weeks). 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.

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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 RESEARCH & MODELS TEAM The Models team builds the foundational models that power our cutting-edge agentic technology. We focus on training techniques to optimize model capabilities specifically for agent applications. This allows us to achieve the best performance at a given inference cost. Our work spans the development of Large Language Models (LLMs) and Vision-Language Models (VLMs), enabling agents to perceive, understand, and act within complex environments. We own the entire pipeline including synthetic data generation, environment design, mid-training, supervised fine-tuning, offline reinforcement learning, online reinforcement learning, reward modelling, transition modelling, etc. Our team also has dedicated MLOps, Infra and Inference support at scale. We focus on improving the long horizon, goal-conditioned instruction-following of large models for GUI/Computer Use agentic interactions, tool use in complex dynamic environments. We regularly ship releases that establish new SOTA in public leaderboards. We parallely operate at the intersection of research and product, translating cutting-edge research into practical solutions that drive the next generation of AI. We are looking for bright, motivated individuals to join us and shape the future of superintelligent AI. Check some of our output * https://hcompany.ai/holo3 * https://hcompany.ai/holotron3 * https://hcompany.ai/h-joins-nemotron-coalition * https://hcompany.ai/meet-holotab KEY RESPONSIBILITIES: * Develop and train advanced LLMs and VLMs, including multimodal architectures * Research and implement training methods for enhanced capabilities like instruction following and tool use * Design and optimize data pipelines and training systems for large-scale distributed training * Collaborate with cross-functional teams to integrate models into agentic AI systems * Evaluate model performance and communicate findings to stakeholders * Stay current with advancements in LLMs, VLMs, and related fields ABOUT YOU: You have a strong research engineer / scientist mindset with experience training and improving large language models at different scales in distributed computing settings whether that’s modelling, data collection, experimenting and ablating, implementing SOTA. TECHNICAL SKILLS: * You have strong programming skills in Python, Rust, or similar; and strong software engineering fundamentals building performant and reliable systems. * Proficient in deep learning frameworks (Pytorch, JAX, TensorFlow). * You can work on different layers of the stack from low-level training backends, data ingestion to ML/RL algorithmic design and implementation. * You know when and where to be rigorous and slower versus when to break and iterate quickly. * You have trained LLMs/VLMs with techniques such as SFT, DPO, RLHF/RLVR, reward modelling, offline RL, distillation, etc. * You have experience with offline and online reinforcement learning in or outside of the context of language models. PREFERRED: * Publications in top-tier AI conferences (e.g., NeurIPS, ICML, CVPR, ACL, ICCV, AAMAS, ...) * Advanced degree (PhD or MSc) in a relevant field (e.g., ML, DL, NLP, CV) * Experience with large-scale distributed training and inference (multi-node, large models, MoE, parallelism strategies, etc) * Experience training models for computer use or other multi-turn and/or multimodal agentic settings. * Extensive experience with reinforcement learning with sparse rewards. * Experience with multi-domain training, data mixture design, curriculum learning, model merging, distillation. SOFT SKILLS: * You are a good communicator, collaborative and low-ego. * You are able to handle a controlled-chaotic environment with a high-degree of between-teams dependencies and collaboration. * You have a go-do attitude and can balance personal conviction/interests with wider team needs. * You don't shy away from hard research or engineering problems. LOCATION: * Paris or London. * This role is hybrid, and you are expected to be in the office 3 days a week on average. * Please expect some travel between offices on a reasonable cadence (e.g., every 4-6 weeks). 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 highly competitive salary. * Unlock opportunities for professional growth, continuous learning, and career development If you want to change the status quo in AI, join us.

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RESEARCH ENGINEER, MODEL INFERENCE & SERVING 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 builds and operates the systems that serve H's foundational models in production. We focus on multimodal inference and serving for Computer Use Agents, optimizing across both the inference engine layer (e.g., vLLM, SGLang) and the model serving layer (e.g., disaggregated inference, intelligent routing). Agentic inference brings constraints around context length, multimodality, and tool calls, which we address by co-designing with the Models team on training-time choices and with the agent teams on how models are deployed. We operate at the intersection of research and production, translating cutting-edge inference techniques into the systems that power H's next generation of agents. We are looking for strong engineers excited about inference to join the team and help shape the systems behind superintelligent AI. KEY RESPONSIBILITIES: * Build and operate the inference stack that serves H's multimodal agentic models * Improve latency, throughput, and cost of model serving across the stack * Research and implement inference techniques tailored to agent workloads * Co-design with the Models team on training-time decisions that affect inference * Collaborate with cross-functional teams to integrate inference into agentic AI products * Evaluate inference, serving, and hardware platforms, and communicate findings to stakeholders * Stay current with advancements in inference, model serving, and accelerator technology REQUIREMENTS: * Technical skills: * Strong software engineering track record * Proficient in Python and at least one systems language (Rust, C++, or Go) * Hands-on experience with deep learning frameworks (PyTorch, JAX), preferably in an industry setting * Solid distributed systems fundamentals * Experience working in a modern cloud environment and with production ML infrastructure (Kubernetes, etc.) * Working knowledge of modern ML, including transformers and multimodal architectures * Research skills: * Research engagement: an advanced degree with research output, or publications at top-tier AI or systems venues (e.g., NeurIPS, ICML, MLSys, OSDI), research internships, or substantive open-source contributions * Soft skills: * Excellent communication and presentation skills * Strong collaboration and teamwork skills * Passion for inference and AI * Preferred qualifications: * Startup experience * Hands-on experience with inference frameworks (vLLM, SGLang, TensorRT-LLM) * Writing or modifying GPU kernels (CUDA, Triton, etc.) * Edge or on-device inference experience (llama.cpp, MLX, ONNX Runtime, etc.) * Experience with quantization, speculative decoding, disaggregated inference or KV-cache compression * Experience with multimodal models and/or agentic systems LOCATION: * Paris or London. * This role is hybrid, and you are expected to be in the office 3 days a week on average. * Please expect some travel between offices on a reasonable cadence (e.g., every 4-6 weeks). WHAT WE OFFER: * Join the exciting journey of shaping the future of AI * 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