Software Engineer I,II,III: Simulations

About the Job
At Lodestar, as a Software Engineer: Simulation, you'll build the environment in which MITHRIL is developed, tested and proven. Every autonomy behaviour we fly is validated in simulation first, which makes the simulator one of the highest-leverage pieces of software in the company: if it isn't faithful, nothing downstream can be trusted.

You'll develop high-fidelity sensor and environment models in Unreal Engine, stand up the software- and hardware-in-the-loop benches that our flight software runs against, and design the distributed services that let scenarios run reproducibly across machines and in CI. You'll work directly with the perception, prediction, decision, and missions teams to decide what needs simulating, at what fidelity, and why.

We proudly have an "extreme ownership" oriented engineering culture.

What You’ll Do
Build and extend the mission simulation environment that Lodestar's autonomy stack is developed and validated against
Develop high-fidelity sensor and environment models - electro-optical cameras, orbital lighting and illumination
Build software-in-the-loop and hardware-in-the-loop test benches so that flight software can be trialed against realistic simulated missions
Design distributed simulation services to run mission scenarios at scale
Own the internal simulation tooling, telemetry, and regression frameworks

Basic Qualifications
We are hiring this role at three levels. All levels require a Bachelor's or Master's degree in Computer Science, Aerospace, Robotics, Mechanical or Electrical Engineering, a related field, or equivalent experience.

Software Engineer I

0–2 years of professional experience in simulation, robotics, games. Can also include Internships and research placements.
Working proficiency in C++ and Python
Exposure to ROS 2 in an academic, research, or professional setting
Understanding of multithreading fundamentals - threads, synchronization primitives, race conditions
Familiarity with 3D game engines (Unreal Engine or Unity) or comparable physics and graphics simulation tooling
Comfortable developing in Linux and with containerised workflows (Docker)

Software Engineer II

2–5 years of industry experience building simulation, robotics, or games.
Strong modern C++ (C++17 or later) alongside Python
Production experience with ROS 2 - node design, DDS middleware, message passing, launch and configuration management
Hands-on SIL and/or HIL experience: building test harnesses and integrating real vehicle or flight software against simulated sensors and actuators
Experience with Unreal Engine for sensor or environment simulation, or equivalent depth in Unity, Isaac Sim, or Gazebo
Experience designing distributed services - inter-process communication, message transport, and orchestration across multiple machines
Demonstrated multithreaded and concurrent programming in a real-time or soft-real-time context

Software Engineer III

6+ years of industry experience, including end-to-end ownership of a simulation stack or a major simulation subsystem
Track record architecting simulation infrastructure - deciding what to model at what fidelity, and defending those trade-offs to engineering stakeholders
Depth in real-time distributed system design: determinism, time synchronisation, clock management, and reproducibility across nodes
Experience standing up HIL benches or SIL pipelines from scratch, including CI integration and automated regression testing
Experience mentoring engineers and setting technical direction across team boundaries
Comfortable deriving requirements from first principles

Preferred Skills & Experience
Familiarity with orbital mechanics and Basilisk
Experience with physics engines and rigid-body dynamics
Sensor modelling experience across electro-optical, LIDAR, RADAR, or RF sensors
Experience with GPU rendering pipelines or CUDA for accelerated simulation and synthetic data generation
Exposure to robotics or space simulation frameworks such as Gazebo, Isaac Sim, Basilisk, or 42
Experience with distributed transports (DDS, Zenoh, gRPC) and time-synchronisation protocols (PTP, NTP)
Experience with Linux, Git, and CI/CD pipelines
Comfortable with containerisation and orchestration tools such as Docker and Kubernetes
Strong understanding of networking and communication protocols for distributed autonomy systems
Candidates should have strong expertise in any or all orbital dynamic simulation, 3D game engines, or distributed simulation architecture (ROS2).

Compensation & Benefits
Our full band structure for this role:
(P1) Entry: $99,000 - $133,000 / year
(P2) Developing: $115,000 - $174,000 / year
(P3) Career: $136,000 - $200,000 / year
(P4) Senior: $175,000 - $250,000 / year
Meaningful equity incentives as part of our employee option pool
Flexible PTO with generous paid vacation, holidays, and sick leave
Comprehensive medical, dental & vision coverage
401(k) retirement plan with company match
Los Angeles
Additional Information
Compensation bands are determined by role, level, location, and alignment with market data. Individual level and base pay is determined on a case-by-case basis and may vary based on job-related skills, education, experience, technical capabilities and internal equity. In addition to base salary, for full-time hires, you may also be eligible for long-term incentives, in the form of stock options , and access to medical, vision and dental coverage, as well as access to a 401(k) retirement plan.