Software Engineer ,II,III: Simulations

Lodestar's mission is to develop the first "Protect and Defend" capability for high-value space assets in orbit. Our flagship productMITHRILis the critical hardware & software necessary to augment any off-the-shelf spacecraft with the ability to autonomously detect, characterise, and reversibly neutralise orbital threats. By building on the proven space heritage of our best-in-class satellite-bus partners and fully integratingMITHRILas a single platform, we deliver a fully autonomous end-to-end protection spacecraft service.

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.

• 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
• Own the internal simulation tooling, telemetry, and regression frameworks

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

• Familiarity with orbital mechanics and Basilisk
• Experience with physics engines and rigid-body dynamics
• Sensor…