Machine Learning Engineer

Focused Energy Job Opportunity Focused Energy is building the future of clean energy through laser-driven inertial fusion. Backed by our $240M Series A — the largest fully secured Series A in the global fusion industry — we are scaling rapidly across multiple geographies. Based in Germany and the US, we have brought together the top scientific and engineering minds using proven technologies to unlock fusion power at commercial scale. Focused Energy is working to realize game-changing scientific innovation that promises to deliver a clean, sustainable and abundant source of power globally. Your Role This role sits at the intersection of ML engineering and computational physics, working within our Software Engineering & Digital Twin environments. You'll collaborate closely with optical engineers, laser and fusion physicists, simulation scientists, and systems engineers to embed data-driven intelligence directly into our Digital Twin architecture. You'll be reducing design risk, shortening development timelines, and unlocking system-level optimization that purely physics-based approaches can't achieve at the speed we need. You will design, build, and deploy machine learning models that enhance, accelerate, and augment our multiphysics simulation environments across our high-energy laser systems, target injection and tracking system, target manufacturing system, and fusion chamber. This will enable faster design cycles, predictive system optimization, and real-time decision support across our laser, targetry, and fusion programs. What You'll Do Surrogate & Reduced-Order Modeling: Design and deploy surrogate and reduced-order models (ROMs) that replace or accelerate high-fidelity multiphysics simulations in the Digital Twin environment Physics-Informed ML: Develop physics-informed machine learning (PIML) and physics-informed neural networks (PINNs) that embed physical constraints (Maxwell's equations, thermodynamics, fluid dynamics) directly into model architectures ML Pipelines: Build and maintain ML pipelines for training, validation, uncertainty quantification (UQ), and continuous model refinement against experimental and simulation data Active Learning & Bayesian Optimization: Implement active learning and Bayesian optimization workflows to intelligently guide design space exploration and reduce costly simulation runs Digital Twin Integration: Integrate trained ML models into the broader Digital Twin framework, interfacing with HPC simulation outputs (COMSOL, ANSYS, custom solvers) and real-time sensor data Anomaly Detection: Develop anomaly detection and predictive diagnostics models to monitor system health and identify off-nominal behavior in laser subsystems Autonomous Optimization: Apply reinforcement learning and Bayesian control approaches to support autonomous or semi-autonomous optimization of laser operating parameters Cross-Functional Collaboration: Collaborate with Digital Twin architects, systems engineers, and optical simulation scientists to ensure ML models meet fidelity, latency, and uncertainty requirements Engineering Rigor: Establish best practices for model versioning, reproducibility, testing, and documentation in a fast-moving research environment Who You Are Must-Haves Master's or PhD in Machine Learning, Computational Physics, Applied Mathematics, Data Science, Computer Science, or a closely related field Proven experience building, training, and deploying ML models for complex physical systems; strong command of deep learning (PyTorch, TensorFlow/JAX), probabilistic models, and uncertainty quantification Expert-level Python; proficiency in C++ or Fortran a plus; experience with HPC environments (batch schedulers, MPI/OpenMP parallelization) Fluency working with PDE-based simulation outputs, time-series sensor data, and high-dimensional parameter spaces typical of multiphysics environments Hands-on experience with Gaussian processes, neural network surrogates, reduced-order models, or equivalent metamodeling techniques Experience building robust ML pipelines for scientific data — including preprocessing, feature engineering, model validation, and deployment Ability to communicate model behavior, confidence intervals, and limitations clearly to physicists, engineers, and non-ML specialists Strong cross-functional team skills; comfort working in an interdisciplinary environment spanning physics, engineering, and software Nice-to-Haves Experience with physics-informed neural networks (PINNs) or neural operators (DeepONet, FNO) applied to physical systems Background in laser physics, plasma physics, high-energy-density science, or related complex physics domains Experience with digital twin platforms and live integration of ML models with simulation environments (e.g., NVIDIA Omniverse, Siemens Xcelerator, ANSYS Twin Builder) Familiarity with multidisciplinary design optimization (MDO) workflows, including Design of Experiments (DoE), sensitivity analysis, and uncertainty propagation Experience applying reinforcement learning to physical system control or optimization Familiarity with Monte Carlo methods and statistical uncertainty quantification frameworks Experience with MLOps tooling (MLflow, Weights & Biases, DVC) in a scientific computing context Interest in fusion energy, advanced laser systems, or high-energy-density physics What We Offer Innovative Technology & Mission: Be part of a cutting-edge company working on groundbreaking research in clean energy and scientific discovery. Career Development: We invest in our people. This is an opportunity to join an early, growing company at the forefront of new technology, where you'll have the opportunity to develop and grow your career. Collaborative Culture: Work with great people in a dynamic, international environment with top-tier scientists, engineers and professionals passionate about solving global challenges. Ownership: Take ownership from day 1 and drive impact by making decisions, solving challenges and shaping the future of our company. Your Success is our Success: We offer a competitive salary and company ownership in the form of stock options, giving you a direct stake in our success and ownership in what we build together. Medical, Dental, Vision: Multiple great plans to pick from that are active come the 1st Day of employment for you and any enrolled dependents. Vacation Days: We support your work-life-balance by granting you Unlimited PTO. Snacks and Drinks: Our office fridges are never empty. Enjoy our healthy snacks and drinks. Retirement Plan: If you decide to enroll in our 401k plan, we will match up to 4% on top of the employee contribution. Equipment: We offer state-of-the-art Windows or Apple Laptops. In addition, you will receive a keyboard, mouse and headset so you are fully equipped from day 1. Events: We organize regular events to foster team bonding, encourage collaboration, and build a strong, supportive company culture. Connect with colleagues across departments, share ideas, and have fun together, both in and outside of the workplace. Focused Energy is an equal opportunity employer committed to creating an inclusive environment. Qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender perception or identity, national origin, age, marital status, protected veteran status, or disability status. Pursuant to the San Francisco Fair Chance Ordinance, Focused Energy will consider for employment qualified applicants with arrest and conviction records. Compensation offered will be determined by factors such as location, level, job-related knowledge, skills, and experience. Certain roles may be eligible for incentive compensation, equity, benefits. Focused Energy