SpaceXSI is looking for Research Scientists to drive effective RL or mid-training research in a small-team setting, owning ambiguous research problems end-to-end.
Compensation
The annual compensation range for this role is $220,000 - $357,000 USD
Responsibilities
Design and run rigorous experiments that turn research ideas into measurable gains in model capability
Improve data recipes through data quality, deduplication, and mixture experiments
Define what makes RL data and rewards good, including grader design and preventing reward hacking
Advance training science, from architecture and scaling experiments to post-training recipes for coding and computer-use agents
Build evals and targeted tasks that expose model weaknesses and guide where the team invests next
Requirements
MS or PhD in CS, ML, math, physics or a related field, or equivalent research experience
Design and execute next-generation data architecture for SpaceXSI’s storage layer, owning databases, caches, and data store strategy.
Compensation
Annual Salary: $140,000 - $225,000 USD
Responsibilities
Design the next-generation data architecture: evolving our storage layer into a partitioned, resilient topology that keeps pace with SpaceXSI's rapid growth
Build query attribution and guardrails: instrumenting every database query by service, catching bad patterns before they hit production, and making it impossible to ship problematic queries without review
Define the "when to use what" strategy for data stores: creating clear guidance and golden pathways so every team picks the right engine for their workload without second-guessing
Own cache infrastructure end-to-end: reliability, capacity planning, and patterns that let product teams move fast without worrying about cache correctness
As a Software Engineer on the Research Tools team, you'll build the infrastructure and applications that enable our researchers to iterate quickly, run complex experiments, and extract insights. This is a full-stack product-engineering role.
Compensation
The annual compensation range for this role is listed below. Annual Salary: $140,000 - $225,000 USD
Responsibilities
Build and maintain the full-stack applications and infrastructure researchers rely on daily, covering experiment setup, feedback collection, and results analysis
Own complete product areas from user needs through design, implementation, and iteration, setting standards for how to build research applications
Create reusable platforms and tools that speed up new research applications, then prototype, ship, and iterate quickly based on real-world usage
Partner with research teams to turn their workflows and pain points into intuitive interfaces and abstractions that make complex research tasks fast and approachable
Requirements
Bachelor's degree in computer science, engineering, math, or scientific discipline
New graduate software engineer to own product work on Grok Bot, Cloud Agents, Cursor and underlying systems.
Compensation
The annual compensation range for this role is listed below.
Annual Salary:
$185,000 USD
Your actual level and base salary will be determined on a case‑by‑case basis and may vary based on the following considerations: job‑related knowledge and skills, education, and experience.
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.
Responsibilities
Add a small UI improvement so AI‑generated code or PRs are easier to read and review
Turn a teammate's rough idea into a working prototype over a few days, then iterate based on feedback
Ship a contained feature (frontend + a bit of backend), then fix bugs and make it feel smoother after people use it
Requirements
Expected graduation in 2027 in CS, software engineering, computer engineering, or a related technical field
Nice to have: Blend strong engineering and AI tools as leverage without giving up correctness
Nice to have: Learn fast, take ownership, and have already done something meaningfully hard early (internships or equivalent industry experience welcome)
Software Engineer, Enterprise PlatformNewCursor · San Francisco, US