Member of Technical Staff, JAX & Compiler

xAI • East Palo Alto, CA

121d • $180,000 - $440,000

About The Position

xAI’s mission is to create AI systems that can accurately understand the universe and aid humanity in its pursuit of knowledge. Our team is small, highly motivated, and focused on engineering excellence. This organization is for individuals who appreciate challenging themselves and thrive on curiosity. We operate with a flat organizational structure. All employees are expected to be hands-on and to contribute directly to the company’s mission. Leadership is given to those who show initiative and consistently deliver excellence. Work ethic and strong prioritization skills are important. All engineers are expected to have strong communication skills. They should be able to concisely and accurately share knowledge with their teammates.

Requirements

• Deep knowledge of JAX core and its interaction with the XLA compiler and runtime.
• Strong understanding of compiler optimizations (e.g., memory assignment, scheduling, fusions) and proficiency with distributed profiling tools like xprof.
• Hands-on experience training large-scale LLMs with JAX (on GPU or TPU) and applying various parallelism strategies to complex use cases.
• Practical experience with kernel compilers such as Triton, Pallas, Mosaic, or CuteDSL.
• Excellent communication skills for close collaboration with our pretraining and reasoning teams.

Responsibilities

• Develop in-house JAX or compiler/runtime features for high-performance large-scale LLM training with different hardware architecture (Hopper, Grace Blackwell).
• Develop and use innovative toolings for debugging distributed programs, profiling train steps and memory consumptions over time.
• Understand CUDA runtime and its interactions with upper-level framework.
• Support a wide range of cutting-edge LLM research/production tasks.

Benefits

• Equity
• Comprehensive medical coverage
• Vision coverage
• Dental coverage
• Access to a 401(k) retirement plan
• Short & long-term disability insurance
• Life insurance
• Various discounts and perks

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Number of Employees: 11-50 employees