Computational Scientist / Scientific Machine Learning

Fusionality; Vaud; Hybrid; CHF 120,000 - 180,000; Full time

Benefits offered by this job

Immigration assistance

Equity compensation

Competitive salary

Relocation assistance

Job summary

Fusionality in Lausanne is seeking a Computational Scientist specialized in Scientific Machine Learning (SciML) to design differentiable solvers for fusion plasma problems. You will work close with control and physics teams to build end-to-end, differentiable solvers in JAX and PyTorch, targeting production-grade performance on GPUs/TPUs.

The role requires a PhD-level or senior researcher with a strong track record in numerical methods, AD, and scientific coding.

Qualifications

• PhD or equivalent research experience in SciML.
• Strong track record in differentiable numerical methods.
• Experience applying SciML to plasma physics is a plus.
• Development of production-grade solvers with testing and validation.

Responsibilities

• Design, implement and validate differentiable solvers in JAX for plasma physics problems (e.g., free-boundary equilibrium, transport, state estimation).
• Make solvers robust and fast for production use via advanced numerical techniques and GPU/TPU optimization.
• Use automatic differentiation for model calibration, parameter estimation and controller design with input from data/controls teams.
• Code ownership: testing, verification against references, packaging and documentation.

Skills

Differentiable solvers

SciML

ODE/PDE methods

GPU/TPU optimization

Automatic differentiation

Python

JAX

PyTorch

Julia

Education

PhD or equivalent research experience (SciML)

Tools

JAX

PyTorch

Julia

Diffrax/Equinox

Job description

Fusionality 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.

• Proficient using Agentic coding and other modern AI technologies to accelerate your work, while remaining accountable for the results.

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.