Software Engineer, RL Training Framework

X.ai; Palo Alto (CA); On-site; USD 180,000 - 440,000; Full time

Benefits offered by this job

Equity

Medical insurance

Vision insurance

Dental insurance

401(k) retirement plan

Disability insurance

Life insurance

Job summary

SpaceXSI is seeking a Software Engineer to build and optimize the RL training framework, supporting everything from quick ablations to full production runs. You will design scales, profile performance, and ensure reliability across the RL stack.

Ideal candidates have experience with Python, Jax, Rust, or C++, and a background in distributed systems or large-scale ML infrastructure. SpaceXSI offers a comprehensive rewards package and equal opportunity employment.

Qualifications

• Experience with Python, Jax, Rust, and/or C++.
• Experience building and debugging large-scale distributed systems.
• Familiarity with RL training infrastructure.

Responsibilities

• Design and implement the systems backing all RL workloads at SpaceXSI, from small scale ablations to production training runs
• Profile, debug, and optimize end-to-end training performance
• Improve scalability and observability of the RL stack

Skills

Python

Jax

Rust

C++

Tools

Distributed systems

Job description

SpaceX was founded under the belief that a future where humanity is out exploring the stars is fundamentally more exciting than one where we are not. Today, SpaceX is actively developing the technologies to make this possible, with the ultimate goal of making life multiplanetary and expanding consciousness to the stars. SpaceXSI is building Super Intelligence to help humanity understand the universe. Our teams are building the full Super Intelligence stack: from our Colossus supercomputers, to Grok models, to our suite of applications, including Grok Bot, Grok Build, Grok Imagine, Grok Voice, and X. We're creating a powerful flywheel where more compute trains better models, better models power more useful products, and what we learn from people using those products shapes what we build next.

SOFTWARE ENGINEER, RL TRAINING FRAMEWORK

The RL infrastructure team is looking for an engineer to help develop our RL training framework.

RESPONSIBILITIES:

• Design and implement the systems backing all RL workloads at SpaceXSI, from small scale ablations to production training runs
• Profile, debug, and optimize end-to-end training performance
• Improve scalability and observability of the RL stack

BASIC QUALIFICATIONS:

• Experience with Python, Jax, Rust, and/or C++

PREFERRED SKILLS AND EXPERIENCE:

• Experience building, debugging, and optimizing efficiency of large-scale distributed systems
• Experience with large scale LLM training infrastructure
• Strong knowledge of reinforcement learning techniques
• Experience with RL numerics
• Comfortable diving into unfamiliar areas and solving problems at all levels of the stack

COMPENSATION AND BENEFITS:

$180,000 - $440,000 USD

Base salary is just one part of our total rewards package at SpaceXSI, which also includes equity, comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, short & long-term disability insurance, life insurance, and various other discounts and perks.

SpaceXSI is an equal opportunity employer.

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