Senior Systems Software Engineer, GPU Compute

About Nebius: 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. 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. 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. The role We’re looking for a Senior Software Systems Engineer to join our team and play a key role in the development of our cutting-edge hyperscaler platform. The GPU & InfiniBand team is responsible for enhancing and optimizing the core components of our Cloud platform, with a specific focus on GPU computing, InfiniBand networks, and the KVM/QEMU stack. You’ll work closely with hardware virtualization and device emulation technologies, ensuring high performance and security in multi-GPU, HPC environments. The role involves analyzing, troubleshooting, and improving infrastructure to support new hardware, fine-tuning system performance, and automating fault detection and resolution in a complex system. In this position, you will be responsible for: • Tuning the performance of GPU clusters and InfiniBand networks to ensure optimal operation in HPC and GPU-based environments.
 • Analyzing and troubleshooting the root cause of issues related to GPUs and InfiniBand networks, and proposing corrective actions.
 • Integrating new hardware into the existing infrastructure, including support for new GPU hardware through software stacks like Kubernetes, QEMU, and KVM.
 • Enhancing automation systems for proactive monitoring, detecting, and resolving issues in GPU and InfiniBand environments.
 • Configuring and managing GPU devices and InfiniBand fabrics, ensuring efficient and reliable operation. We expect you to have: • 5+ years of professional experience in system-level software development (focused on performance optimization, low-level programming).
 • 3+ years of hands-on experience with Linux systems (administration, troubleshooting, and performance tuning).
 • In-depth understanding of server architecture, including PCIe devices, NICs, Linux OS/Kernel, and high-performance computing (HPC) systems.
 • Strong proficiency in one or more performance-oriented programming languages (C/C++, Go, Python). It would be a plus if you have: • Experience with GPU end-to-end testing in a cluster environment using InfiniBand networking.
 • Proven track record of analyzing and optimizing the performance of HPC workloads (e.g., simulations, data analysis, AI/ML workloads).
 • Familiarity with RDMA, RoCE, and InfiniBand protocols for high-performance communication.
 • Background in Software-Defined Networking (SDN) and experience with HPC cluster networking .
 • Understanding of QEMU/KVM virtualization and managing virtualized environments.
 • Experience with deep learning frameworks such as PyTorch and TensorFlow , and their integration with HPC systems.
 • Familiarity with collective communication libraries like MPI and NCCL for distributed computing. We offer competitive salaries ranging from $170k-$300k + equity based on your experience. We conduct coding interviews as part of the process. #LI-LH2 Benefits & Perks: • Competitive compensation • Career growth and learning opportunities • Flexibility and ownership • Collaborative and innovative culture • Opportunity to work on imp