Software Engineer - Kernels/CUDA (C++)

Details

SpaceXAI is building one of the world’s largest AI supercomputers from the ground up. As part of the Compute Infrastructure team, this role owns both the raw GPU supercomputer and the platform layer that runs on top of it. The work spans low-level GPU kernel optimization, Linux kernel internals, large-scale orchestration, and virtualization to make training and inference faster, more reliable, and more scalable.

Responsibilities

• Design, build, and optimize massive GPU clusters for extreme-scale training and inference workloads.
• Develop and tune low-level CUDA kernels, including GeMM and Attention, using CUTLASS, Tensor Cores, and Nsight for maximum performance.
• Profile, debug, and eliminate bottlenecks across the GPU memory hierarchy, networking fabric, filesystems, and multi-GPU operation.
• Collaborate closely with AI research teams to deliver production-grade performance and scalability.

Requirements

• Deep low-level systems programming experience with C, C++, PTX, and SASS.
• Strong experience with large-scale GPU clusters or distributed compute infrastructure at production scale.
• Hands-on experience with GPU kernel optimization, including CUTLASS, custom kernels, and Nsight profiling.
• A track record of building or running high-performance infrastructure for AI workloads, including training or inference platforms.
• Ability to reason from first principles and optimize for both memory-bound and compute-bound scenarios.
• Strong communication skills, work ethic, prioritization skills, curiosity, and a hands-on approach.

Benefits

• Base salary of $180,000–$440,000 USD.
• Equity.
• Comprehensive medical, vision, and dental coverage.
• Access to a 401(k) retirement plan.
• Short- and long-term disability insurance.
• Life insurance.
• Various discounts and perks.
• Equal opportunity employment.