Member of Technical Staff — Heterogenous Hardware

RadixArk is seeking a Member of Technical Staff: Accelerator Systems to push the limits of performance for frontier AI systems. The role involves optimizing and maintaining the RadixArk infrastructure stack across various hardware platforms, including NVIDIA and AMD GPUs, and requires deep expertise in accelerator programming models.

Responsibilities:

• Bring up RadixArk's inference and training systems on new accelerator platforms and drive them to competitive performance
• Design hardware abstractions that let a single codebase stay fast across vendors without forking
• Port and optimize kernels across programming models and memory architectures
• Build cross-platform benchmarking, profiling, and regression detection so performance claims hold up on every target
• Debug numerical divergence and correctness gaps between platforms
• Work with vendor engineering teams on pre-release hardware, compiler and driver issues, and roadmap feedback
• Partner with kernel, runtime, distributed systems, and product engineers to land performance wins end to end
• Serve as the internal source of truth on what each platform is actually good at
• Contribute hardware-specific optimizations, benchmarks, and portability work back to open-source SGLang and Miles