Senior ML Engineer (Token Factory)

<div class="content-intro"><p><strong>About Nebius:</strong></p> <p>Nebius is leading a new era in cloud infrastructure for the global AI economy. We are building a full-stack AI cloud platform that supports developers and enterprises from data and model training through to production deployment, without the cost and complexity of building large in-house AI/ML infrastructure.</p> <p>Built by engineers, for engineers. From large-scale GPU orchestration to inference optimization, we own the hard problems across compute, storage, networking and applied AI.</p> <p>Listed on Nasdaq (NBIS) and headquartered in Amsterdam, we have a global footprint with R&D hubs across Europe, the UK, North America and Israel. Our team of 1,500+ includes hundreds of engineers with deep expertise across hardware, software and AI R&D.</p></div><p><strong>The role</strong></p> <p>Token Factory is a part of Nebius Cloud, one of the world's largest GPU clouds, running tens of thousands of GPUs. We are building a high-performance inference and fine-tuning platform designed to push foundation models to their hardware limits. Our mission is to maximize throughput, minimise latency, and optimise cost-per-token across tens of thousands of GPUs.</p> <p> </p> <p><strong>Some directions we are currently working on, and which you can be a part of:</strong></p> <ul> <li>Inference Optimization: Identifying LLM inference bottlenecks to drive production speedups. Squeezing the maximum performance for a wide range of LLM architectures at scale (e.g., GPT-OSS, Kimi K2.5, DeepSeek V3.1/V3.2, GLM-5).</li> <li>Inference engines support: Implement novel speculative decoding architectures, optimise components of various LLM designs (dense/MoE, autoregressive/parallel), and contribute to open-source inference engines.</li> <li>Low Precision Training & Inference: Design and productionise low-precision (FP8, NVFP4/MXFP4) training and inference pipelines with measurable gains in throughput and cost-efficiency.</li> </ul> <p> </p> <p><strong>We expect you to have:</strong></p> <ul> <li>A profound understanding of theoretical foundations of machine learning and transformer architecture.</li> <li>Experience profiling GPU workloads using Nsight, PyTorch profiler, or similar tools</li> <li>Understanding of GPU memory hierarchy and compute/memory tradeoffs</li> <li>Familiarity with important ideas in LLM space, such as MHA, RoPE, KV-cache, Flash Attention, and quantisation</li> <li> Understanding of performance aspects of large neural network training (sharding strategies, custom kernels, hardware features etc.)</li> <li> Strong software engineering skills (we mostly use Python)</li> <li>Deep experience with modern deep learning frameworks</li> <li>Proficiency in contemporary software engineering approaches, including CI/CD, version control and unit testing</li> <li>Strong communication and leadership abilities</li> </ul> <p> </p> <p><strong>Nice to have:</strong></p> <ul> <li>Experience working with open-source inference engines (vLLM, SGLang, TensorRT-LLM), including contributions</li> <li>Experience with kernel languages or DSLs such as Triton, Cute, CUTLASS, CUDA</li> <li>A track record of building and delivering products (not necessarily ML-related) in a dynamic startup-like environment.</li> <li>Strong engineering skills, including experience in developing large distributed systems or high-load web services.</li> <li>Open-source projects that showcase your engineering prowess</li> <li> Excellent command of the English language, alongside superior writing, articulation, and communication skills.</li> </ul> <p> </p> <p> </p><div class="content-conclusion"><p><strong>Benefits & Perks:</strong></p> <ul> <li>Competitive compensation</li> <li>Career growth and learning opportunities</li> <li>Flexibility and ownership</li> <li>Collaborative and innovative culture</li> <li>Opportunity to work on impactful AI projects</li> <li>International environment and talented teams</li> </ul> <p><strong>What's it like to work at Nebius:</strong></p> <p>Fast moving - Bold thinking - Constant growth - Meaningful impact - Trust and real ownership - Opportunity to shape the fu