Principal Network Engineer

Principal Network Engineer – AI InfrastructureThe Network Operations and Engineering teams at Nscale operate some of the most demanding networking environments in the industry, supporting tightly coupled GPU clusters where network performance directly impacts customer outcomes.We're looking for a Principal Network Engineer – AI Infrastructure to provide technical leadership across Nscale's high-speed networking domain. This role is focused on owning the reliability, scalability, and long-term evolution of our Infiniband and RDMA-based network fabrics. You will operate as a technical authority, influencing architecture, standards, and operational practices across teams while tackling the most complex network challenges in the platform.What You'll Be DoingOwning the technical direction and operational strategy for Nscale's AI interconnect networksDesigning, reviewing, and evolving large-scale Infiniband and RoCE fabric architectures to support future growth and workload demandsActing as the senior escalation point for the most complex network incidents, guiding deep technical investigations and systemic fixesDriving cross-team initiatives to improve fabric reliability, performance predictability, and operational maturityDefining standards for hardware configuration, congestion control, routing, firmware lifecycle management, and change safetyPartnering with SRE, Compute Platform, and Network Architecture teams to influence end-to-end system designMentoring senior and mid-level network engineers, raising the bar for operational rigor and technical excellenceDriving measurable improvements in uptime, latency consistency, capacity efficiency, and incident reductionAbout You (Skills / Qualifications)10+ years of experience in network engineering, with deep focus on HPC, AI, or hyperscale data centre networkingExpert-level operational and architectural experience with Infiniband and/or large-scale RoCE fabricsDeep understanding of RDMA internals, congestion management, and fabric-level failure modesStrong expertise in modern data centre routing and control planes (BGP, OSPF, ECMP)Proven ability to debug and resolve cross-layer issues spanning hardware, firmware, kernel, and application communication librariesDemonstrated ability to lead complex technical initiatives across teams without direct authorityA systems-level mindset, balancing performance, reliability, scalability, and operational costNice to HaveExtensive experience with NVIDIA/Mellanox networking platforms in production AI or HPC environmentsDeep familiarity with distributed training frameworks and GPU communication patternsExperience designing network observability systems for high-cardinality, high-throughput environmentsPrior experience influencing platform or infrastructure strategy at scaleWhat We Can Offer YouHighly competitive package (base + equity) with reviews every 12 months.Join the fastest-growing tech startup, your chance to push boundaries, collaborate with brilliant minds, and make your mark on cutting-edge AI.Expect a dynamic progression plan tailored to your ambitions. Grow by trying new things, leading, challenging the status quo, and owning your impact, always with our full support.Equal Opportunities StatementWe strongly encourage applications from people of colour, the LGBTQ+ community, people with disabilities, neurodivergent people, parents, carers, and people from lower socio-economic backgrounds. If there's anything we can do to accommodate your specific situation, please let us know.