Simulation Engineer

Helsing; Greater London; On-site; GBP 75,000 - 115,000; Full time

Job summary

Helsing, a defence AI company in Greater London, is seeking a software engineer to build and maintain the simulation stack for large-scale virtual worlds.

You will implement production code for the platform and the models running inside it, balancing fidelity, performance, and reliability while collaborating with multiple teams across the organisation.

Qualifications

• Built real simulations beyond toy projects with game engines like Unreal/Unity/Godot.
• Applied production-quality software engineering practices to simulation work.
• Able to translate domain requirements into reusable simulation models.
• Reason about trade-offs between fidelity and throughput in complex simulations.
• Experience structuring simulations for long-term maintenance and extensibility.

Responsibilities

• Write production code for the simulation platform internals and models.
• Integrate 3D models, animations, and physics into the simulation stack.
• Translate mission requirements from domain experts into reusable simulation models.
• Collaborate across engineering teams to ensure robust, scalable simulation outcomes.

Skills

Realistic simulations

Game engines

Production code

Version control

Fidelity vs throughput

Requirements translation

Tools

Unreal Engine

Unity

Godot

Job description

Who We Are

Helsing is a defence AI company. Our mission is to protect our democracies. We aim to achieve technological leadership, so that open societies can continue to make sovereign decisions and control their ethical standards.

As democracies, we believe we have a special responsibility to be thoughtful about the development and deployment of powerful technologies like AI. We take this responsibility seriously.

We are an ambitious and committed team of engineers, AI specialists and customer-facing programme managers. We are looking for mission-driven people to join our European teams – and apply their skills to solve the most complex and impactful problems. We embrace an open and transparent culture that welcomes healthy debates on the use of technology in defence, its benefits, and its ethical implications.

The role

At Helsing we use simulation to train and test autonomy at scale, long before anything touches real hardware. You will be part of a team that owns a system for simulating large-scale 3D worlds containing hundreds of actors, rendered in real time.

You will work on the internals of the simulation stack, including modelling of vehicles and other actors, integration of high-fidelity models from domain experts, sensor and environment simulation, networking, and interfacing with other components in a distributed system.

Typical examples of day-to-day responsibilities include:

• Building and maintaining simulation platform internals: subsystem architecture, replication and multiplayer, performance profiling, and the interfaces used by other systems to orchestrate simulation.
• Composing simulated platforms from sensor, communications, situational awareness, effector, and control-loop models, and reasoning about the underlying physics such as flight dynamics, rigid-body behaviour, collision, and line of sight.
• Owning the trade-off between fidelity, throughput, and engineering cost, choosing the right point for each use case and validating the result against subject matter experts, integration tests, or downstream outcomes.
• Integrating 3D models, animations, and effects from our Content Engineers into the simulation.
• Investigating simulation bugs in order to bridge the gap from our simulation to a reference model.

The day-to-day

You will write production code that shapes both the simulation platform and the models running inside it, and you will decide how each piece of work is validated.

You will also translate mission requirements from subject matter experts into reusable simulation models, and make sure those models remain useful to the teams using simulation as part of their stacks.

You will contribute to high-impact projects and collaborate with people across many teams and backgrounds.

You should apply if you

• Have built real simulations well beyond toy projects, especially with game engines such as Unreal, Unity, or Godot, including gameplay frameworks, replication, and profiling tooling.
• Write production code and bring proper software engineering practice into simulation work, including version control discipline, resolving ambiguity, and designing for the long term rather than the next demo.
• Reason fluently about the trade-off between physical fidelity and simulation throughput.
• Translate input from domain experts into models and behaviours, and know when real-world fidelity is needed and when it is expensive noise.
• Judge a simulation by what it enables rather than by whether it passes its tests, and treat a simulation that quietly misleads its users as a serious failure.

Note: We operate at an intersection where women, as well as other minority groups, are systematically under-represented. We encourage you to apply even if you don’t meet all the listed qualifications; ability and impact cannot be summarised in a few bullet points.

Nice to have

• Experience with entity-component-system architectures or agent-based modelling.
• Experience with distributed simulation standards such as HLA, DIS, RPR-FOM, NETN, or FMI.
• Background in physics-heavy simulation, for example CFD, finite element methods, multi-body dynamics, or trajectory and 6DoF modelling.
• Experience with RF, electronic warfare, or radar simulation, including propagation and signal processing chains.
• Familiarity with reinforcement learning environment APIs, or with software-in-the-loop and hardware-in-the-loop validation.
• Experience with Rust, CUDA, or MATLAB and Simulink.

Helsing's Candidate Privacy and Confidentiality Regime can be found here.