Senior Network Engineer

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. *]:pointer-events-auto scroll-mt-[calc(var(--header-height)+min(200px,max(70px,20svh)))]" data-turn-id="request-WEB:15eea77a-430d-424c-853f-ddcbc7d37ef3-17" data-testid="conversation-turn-8" data-scroll-anchor="true" data-turn="assistant"> The role: We are looking for a Senior Network Engineer to design, build, and operate large-scale, high-performance data center networks supporting GPU-dense AI workloads. You will take end-to-end ownership of service provider–grade and CLOS-based network infrastructure, ensuring reliability, scalability, and predictable performance across distributed environments. This role requires deep expertise in routing, switching, and modern data center fabrics, with a strong focus on production operations, root cause analysis, and continuous improvement of network systems. Your responsibilities will include: Design and evolve scalable data center network architectures (CLOS/leaf-spine) for high-throughput, low-latency environments Own end-to-end deployment and lifecycle management of routing and switching infrastructure across production environments Develop and maintain network design documentation, standards, and operational procedures Plan, execute, and validate network infrastructure testing, including vendor evaluation and benchmarking Diagnose and resolve complex network issues across the TCP/IPv4/v6 stack in large-scale distributed environments Optimize traffic engineering, ECMP, and load balancing strategies to ensure efficient utilization of network resources Implement and operate MPLS-based technologies, including L3 VPNs and segment routing (SR-MPLS, SRv6) Collaborate with hardware, systems, and software teams to integrate networking with compute and storage infrastructure Automate network operations and workflows to improve reliability, scalability, and operational efficiency Ensure high availability and performance of production networks through proactive monitoring and continuous improvement What we expect you to have: Expert-level knowledge (CCIE/JNCIE or equivalent) in MPLS, routing, and switching for service provider and data center networks Strong experience with Ethernet switching, VXLAN, and modern cloud overlay networking technologies Deep expertise in routing protocols including BGP and IS-IS Hands-on experience with segment routing (SR-MPLS, SRv6), L3 MPLS VPNs, and ECMP-based traffic balancing Proven experience designing and documenting large-scale network architectures Experience developing and executing network testing strategies and validating vendor solutions Strong troubleshooting skills across the TCP/IPv4/v6 stack in CLOS-based data center environments Solid understanding of network hardware architecture, QoS mechanisms, and packet processing pipelines Hands-on experience with network equipment from vendors such as Juniper, Arista, Huawei, and Mellanox Working proficiency in English It will be an added bonus if you have: Working proficiency in an additional European language Experience with public cloud networking and GPU/InfiniBand environments Knowledge of software-defined networking (SDN) overlays in cloud environments Proficiency in Python, Go, or other programming languages in Linux environments Experience using programming la…