Member of Technical Staff — Kernel​/Compiler​/CommunicationPalo Alto, CA

Member of Technical Staff — Kernel / Compiler / Communication

Radix Ark is seeking a deeply technical engineer who pushes the limits of performance for frontier AI systems. You will work at the lowest layers of the stack—kernels, runtimes, compilers, and communication libraries—to unlock maximum efficiency from modern accelerators and interconnects.

This role is critical to scaling training and inference across thousands of GPUs, where microseconds and memory bandwidth matter. Your work will directly shape the performance envelope of next‑generation AI systems.

We are looking for an engineer who enjoys working close to hardware and solving performance problems that most engineers never encounter.

• Design and implement high-performance kernels for AI workloads
• Optimize compiler and runtime stacks for ML systems
• Improve communication efficiency across large GPU clusters
• Reduce latency and increase throughput for distributed workloads
• Profile and eliminate system bottlenecks across the stack
• Collaborate with training and inference teams on performance optimization
• Develop tooling for profiling and performance analysis
• Contribute to long-term architecture for performance‑critical systems
• Push the limits of hardware–software co‑design

• 5+ years of experience in systems, compiler, or performance engineering
• Strong expertise in CUDA or accelerator programming
• Deep understanding of GPU architecture and memory hierarchy
• Experience writing or optimizing high-performance kernels
• Strong background in compilers, runtimes, or code generation
• Experience with distributed communication libraries (NCCL, MPI, RCCL, etc.)
• Solid knowledge of networking and interconnect technologies
• Proficiency in C++ and Python
• Strong debugging and profiling skills at system level

• Experience with Triton, TVM, XLA, or MLIR
• Experience building compiler passes or IR transformations
• Familiarity with NVLink, Infini Band, or RDMA
• Experience optimizing collective communication at scale
• Background in HPC or performance‑critical systems
• Contributions to kernel/compiler/ML systems open source
• Experience scaling workloads to 1000+ GPUs
• Experience with mixed‑precision or quantized kernels

Radix Ark is an infrastructure‑first company built by engineers who ship production AI systems. We develop open systems for inference and training and have already optimized kernels serving billions of tokens daily.

We offer competitive compensation with meaningful equity, comprehensive benefits, and flexible work arrangements. Compensation depends on location, experience, and level.

Radix Ark is an Equal Opportunity Employer and is proud to offer equal employment opportunity to everyone regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, veteran status, and more.