Simulation Engineer | Particle Dynamics

At Feyer, physics simulators are the environments in which our AI systems learn what is physically possible. Their speed, accuracy, and reliability determine the scale and quality of every experiment we can run.

In this role, you will own core parts of a charged-particle simulation stack, from field models and trajectory integration to GPU implementation, validation, and performance. You will work closely with colleagues in physics, AI, and engineering while remaining deeply focused on building exceptional simulation software.

What you will work on

• Own charged-particle simulation methods: design and implement models of electric and RF fields, trajectories, interactions, collisions, and loss mechanisms.
• Run simulations at scale: build GPU-accelerated solvers in JAX for large particle ensembles, complex geometries, and repeated workloads.
• Establish trustworthy validation: quantify convergence, stability, and physical accuracy against analytical references, established solvers, and measured instrument data.
• Model real systems: represent geometry, timing, control parameters, signal formation, and operating conditions without losing computational efficiency.
• Build durable scientific software: create modular APIs, benchmarks, tests, and documentation that make the simulator easy to extend and hard to misuse.

What you bring

• A strong foundation in physics, applied mathematics, computer science, or a related engineering field.
• Hands-on experience with numerical methods, computational physics, scientific software, or adjacent simulation work.
• Knowledge of particle dynamics, electrostatics, RF systems, vacuum instrumentation, signal formation, or a closely related field.
• A careful approach to verification, numerical testing, and building reliable simulation software.

Nice to have

• Experience with particle tracing, field solvers, finite-element or boundary-element methods, or particle-in-cell techniques.
• Experience with charged-particle instruments, vacuum systems, scientific instrumentation, or experimental physics.
• Experience designing and profiling efficient JAX programs using automatic differentiation and transformations such as jit, vmap, and multi-device sharding.
• Experience scaling simulation workloads across multiple GPUs or compute nodes.

What we offer

• Own a simulation stack central to Feyer's AI systems, with the freedom to shape its numerical methods and software architecture.
• Access to hundreds of thousands of GPU-hours for large-scale simulation and AI experiments.
• Work directly with an experienced founding team in a small interdisciplinary group spanning physics, AI, and engineering.
• A competitive salary that reflects your experience and impact.