Software Engineer, Evaluation Infrastructure

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

Benefits offered by this job

Equity

Comprehensive medical

Vision insurance

Dental coverage

401(k) retirement plan

Disability insurance

Life insurance

Employee discounts

Job summary

SpaceXSI is hiring a Software Engineer for Evaluation Infrastructure to design and maintain scalable evaluation systems for our AI models. You will write production-grade code across Python, PyTorch, JAX, Rust, or C++, and work with teams to improve evaluation signals and tooling.

You will tackle performance bottlenecks in the eval pipeline, optimize resource orchestration, and help advance our large-scale model evaluation capabilities while aligning with our distributed systems strategy.

Qualifications

• Production-quality Python, PyTorch, JAX, Rust, or C++ programming experience.
• Experience building and debugging large-scale distributed systems.
• Ability to optimize evaluation infrastructure performance.

Responsibilities

• Build reliable, scalable evaluation infrastructure for model assessments.
• Collaborate with modeling and evaluation teams on new evals and tooling.
• Identify bottlenecks in the eval infrastructure stack and optimize them.

Skills

Python

PyTorch

JAX

Rust

C++

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, EVALUATION INFRASTRUCTURE

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

RESPONSIBILITIES:

• Build highly reliable, efficient, and easy to use infrastructure that runs all our evaluations at scale
• Collaborate closely with modeling & evaluation teams on developing new evals, maintaining evaluation signal quality, and building internal tooling to support training our next-generation of models
• Identify and resolve performance bottlenecks in all layers of the eval infrastructure stack, including inference, capacity fleet management, asynchronous eval orchestration, and more

BASIC QUALIFICATIONS:

• Experience writing production-quality code in Python, PyTorch, JAX, Rust, or C++

PREFERRED SKILLS AND EXPERIENCE:

• Experience in building, debugging, and optimizing efficiency of large-scale distributed systems
• Willingness to dive deep and solve hard problems at all levels of the stack
• Experience in LLM inference
• Experience in GPU compute management, workload scheduling, and dynamic resource optimization
• Experience in developing interfaces for comparing models and evals

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.

• equity
• comprehensive medical
• vision
• dental coverage
• access to a 401(k) retirement plan
• short & long-term disability insurance
• life insurance
• various other discounts and perks

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