Simulation Engineer - Physics Modeling

The role

You will close the gap between how NEO behaves in simulation and how it behaves in the world. You will build and validate dynamics, material, and sensor models to ensure simulation results hold up on hardware.

What you will do

• Improve contact dynamics, articulated body models, and actuator and transmission fidelity.
• Model soft contact and structural compliance for grasping and contact-rich behavior.
• Model the sensing path including noise, bias, dropout, latency, and sample timing.
• Establish benchmarks and real-robot comparisons to quantify sim-to-real error.
• Decide which discrepancies to model faithfully or randomize over.
• Make runs reproducible for debugging and regression testing.
• Optimize physics and rendering and deliver synthetic data pipelines.
• Write tested, maintainable simulation code.
• Set the approach for problem areas and defend tradeoffs.

Required qualifications

• Strong programming in Python, C++, or similar languages.
• Experience building environments or benchmarks using robotics simulators (MuJoCo, PyBullet, Isaac Sim, or equivalent).
• Demonstrated experience improving simulation fidelity and closing the sim-to-real gap for behavior that had to work on physical hardware.
• Experience modeling sensors and their failure modes in simulation, including noise, bias, latency, and dropout.
• Experience improving the performance of physics simulators or rendering pipelines.
• Strong testing practices for simulation stacks used in robot learning.
• 5+ years of relevant industry experience, or an advanced degree plus equivalent hands-on experience.

Nice to have

• Experience with system identification on real hardware, and with turning measured parameters into simulation models
• Experience with procedural environment generation or other techniques for scaling diverse simulation data production
• Familiarity with differentiable simulation, learned or neural simulators, or GPU-accelerated physics such as Warp or JAX-based frameworks
• Background in legged locomotion, dexterous manipulation, or contact-rich and deformable-body simulation

Benefits

• Comprehensive medical, dental, and vision coverage
• Generous paid time off, company holidays, and parental leave
• 401(k) plan with company match (100% on the first 3% of contributions, 50% on the next 2%)
• Flexible Spending Accounts (FSA) and Health Savings Accounts (HSA) options
• Commuter benefits (transit and parking)
• Short-term and long-term disability, and life insurance
• Employee Assistance Program (EAP) for mental health, financial, and personal support
• Onsite snacks and catered lunches

About the company

1X builds humanoid robots that work in homes to do chores and handle tasks. They are developing NEO, a flagship home robot designed to move, learn, and operate in the real world.