Software Engineer, Evaluation Infrastructure

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. SpaceXSI is an equal opportunity employer. For details on data processing, view our Recruitment Privacy Notice .