Computational Scientist / Scientific Machine Learning

Fusionality; Lausanne; On-site; CHF 100,000 - 170,000; Full time

Benefits offered by this job

Immigration assistance

Equity compensation

Job summary

Fusionality in Lausanne, Switzerland, is building a measurement, simulation, and control stack for future fusion reactors. We seek a PhD-level or senior Computational Scientist specializing in Scientific Machine Learning (SciML) to develop fast, differentiable solvers and run them on real plasma data and control systems.

You will implement solvers in JAX (with Julia or PyTorch as a fallback), advance numerical methods for ODEs/PDEs, and ensure production-grade performance.

Qualifications

• PhD or equivalent research experience in SciML or related field.
• Strong background in numerical methods for ODEs/PDEs and implicit solvers.
• Experience with differentiable frameworks (JAX, Julia, PyTorch) and large codebases.

Responsibilities

• Design, implement and validate differentiable solvers in JAX for plasma physics problems.
• Optimize performance for production use on GPU/TPU with advanced numerical techniques.
• Apply automatic differentiation for model calibration and controller design with experimental data.
• Ensure code quality, testing, verification against reference solutions, packaging and documentation.

Skills

SciML

Differentiable solvers

JAX

ODEs & PDEs

Python

Education

PhD or equivalent

Tools

JAX

Julia

PyTorch

Job description

the company is building the measurement, simulation, and control stack for the fusion energy reactors of the future.

Spun out of EPFL's Swiss Plasma Center and backed by top investors, our technology enables reliable operation, real-time monitoring, and analysis of high-temperature plasmas in fusion devices. We are founded by world-class experts at the intersection of fusion physics, advanced control, and AI (ex-Google DeepMind, EPFL). We are assembling a founding engineering team in Lausanne to build our core technology platform.

We are looking for a Computational Scientist specialized in Scientific Machine Learning (SciML) to join our team. This job is for you if you know how to write numerical solvers that are fast, correct and differentiable end to end, and want to see them run against real plasma data and inside real control systems.

We are looking for a PhD-level or senior computational researcher for this role.

Responsibilities

• Design, implement and validate differentiable solvers in JAX for plasma physics problems such as free-boundary equilibrium, transport and state estimation.
• Make them robust and fast enough for production use via advanced numerical techniques for differential equation time stepping, as well as optimization of GPU/TPU performance.
• Using automatic differentiation for model calibration against experimental data, parameter estimation and controller design and optimization, working with our data and control engineers.
• Code ownership: quality, testing, verification against reference solutions, packaging and documentation.

Requirements

• Substantial code written in a differentiable framework. Our stack is in JAX, Julia or PyTorch experts are very welcome if they're happy to switch.
• Strong background in numerical methods for ODEs and PDEs: discretisation, stiff and implicit solvers, nonlinear and sparse linear solvers.
• Demonstrated ability to operate at the frontier of SciML, Universal Differential Equations, Neural ODEs, and other emerging hybrid data-driven/mechanistic paradigms.
• Evidence of independent work at the highest level: a PhD or thesis, published code that is used by others, or an industry project you owned.
• Experience in the following fields an advantage but not strictly required:
• The JAX ecosystem: Diffrax, Equinox, Optax, Lineax.
• Plasma, fluid, electromagnetic, or other multiphysics simulation.
• Having led the design of a scientific codebase used by others.

What we offer

• Play a key role at a dynamic, fast-growing startup, shaping the technical solutions and products from the ground up.
• Build cutting-edge technology to monitor and control plasmas in real fusion devices, working side-by-side with leading plasma and control experts.
• Great working conditions, located in Lausanne, Switzerland, a city and country known for its high quality of life.
• Competitive salary and equity compensation and benefits including immigration assistance.