Lead Software Systems Engineer - GPU Performance

Details

Nebius is building a full-stack AI cloud platform and is looking for a Lead Software Systems Engineer - GPU Performance to help build its hyperscaler platform. You will work across core components while analyzing and optimizing the performance of large-scale GPU clusters at the intersection of hardware and software.

You will operate across the full stack—from hardware and system software to networking (InfiniBand/RoCE), virtualization (KVM/QEMU), and distributed communication layers (e.g., MPI, NCCL).

Responsibilities

• Focus on understanding system behavior across multiple layers, identifying performance bottlenecks, and driving improvements that shape how clusters are built, operated, tuned, and validated.
• Investigate and troubleshoot performance issues of GPU clusters under real workloads (training and inference).
• Evaluate and integrate new hardware, system configurations, and tuning approaches through the software stack.
• Support complex performance-related escalations from internal teams and customers.
• Work closely with infrastructure, software engineering, and hardware vendor teams (e.g., NVIDIA, Mellox, Intel).
• Contribute to hardware and cluster qualification (acceptance) to ensure systems meet performance expectations.

Requirements

• 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).

Coding interviews are part of the process.

Benefits

• Health insurance: 100% company-paid medical, dental and vision coverage for employees and families.
• 401(k) plan: up to 4% company match with immediate vesting.
• Parental leave: 20 weeks paid for primary caregivers, 12 weeks for secondary caregivers.
• Remote work reimbursement: up to $85/month for mobile and internet.
• Disability & life insurance: company-paid short-term, long-term and life insurance coverage.

Benefits & perks also include: competitive compensation, career growth and learning opportunities, flexibility and ownership, collaborative and innovative culture, opportunity to work on impactful AI projects, and an international environment and talented teams.