Scientist, Model Systems

ABOUT US PhysicsX is a deep-tech company with roots in numerical physics and Formula One, dedicated to accelerating hardware innovation at the speed of software. We are building an AI-driven simulation software stack for engineering and manufacturing across advanced industries. By enabling high-fidelity, multi-physics simulation through AI inference across the entire engineering lifecycle, PhysicsX unlocks new levels of optimization and automation in design, manufacturing, and operations — empowering engineers to push the boundaries of possibility. Our customers include leading innovators in Aerospace & Defense, Materials, Energy, Semiconductors, and Automotive. NOTE: WE ARE CURRENTLY RECRUITING FOR MULTIPLE LEVELS AND POSITIONS, HOWEVER PLEASE ONLY APPLY FOR THE ROLE THAT BEST ALIGNS WITH YOUR SKILLSET AND CAREER GOALS. WHAT YOU WILL DO  * Work closely with a multi-disciplinary team ranging form computational chemists with varied domain expertise to machine learning engineers to employ and advance the state-of-the-art machine learning techniques for solving a variety of problems in materials. * Develop and apply machine learning interatomic potentials (MLIPs) to model atomistic systems, leveraging and extending state-of-the-art frameworks and benchmark datasets. * Design and run experiments on large-scale chemistry and materials datasets, iterating on model architectures to improve accuracy, transferability, and generalisation across systems. * Own research workstreams at different levels of scope, depending on seniority, from model development through to evaluation on real-world materials problems. * Collaborate with the broader research team to ensure your models are robust, reproducible, and translatable into production-ready pipelines. * Work on high-performance computing infrastructure to handle the scale and complexity of atomistic simulations and generative modelling tasks. * Communicate your work internally and externally — through paper publications, industry workshops, and customer conversations — tailoring the message for both academic and non-academic audiences. * Mentor colleagues with less experience in computational chemistry or materials ML as the team grows.   WHAT YOU BRING TO THE TABLE * Enthusiasm for applying machine learning to real-world materials science and computational chemistry challenges, with a genuine interest in seeing your research have industry impact. * Ability to scope and effectively deliver research projects, balancing rigour with pragmatism. * Strong problem-solving skills and the ability to move quickly from a materials or chemistry challenge to a tractable computational formulation. * Excellent collaboration and communication skills — with research colleagues, engineers, and customers alike. * PhD in computational chemistry, physics, materials science or a closely related field. * Hands-on experience in using and fine-tuning at least one MLIP backend such as MACE or FAIRChem/OCP and their integration into larger computational framework. * Direct experience with established chemistry and materials benchmark datasets, such as OC20, OC22, or the Materials Project. * Proficiency in Python and experience working in high-performance computing environments as well as experience in contributing towards a large multi-module codebase * Experience with generative models preferably applied to molecular or materials systems. WHAT WE OFFER Build what actually matters Help shape an AI-native engineering company at a formative stage, tackling problems that genuinely matter for industry and society. This is work with real-world impact - and something you can be proud to stand behind. Learn alongside exceptional people Work with a high-caliber, collaborative team of engineers, scientists, and operators who care deeply about doing great work, and about helping each other get better. We come from diverse backgrounds, but we share a commitment to operating at the highest level and addressing some of the most complex challenges out there. If you’re ambitious, thoughtful, and driven by impact, you’ll feel at home. Influence over hierarchy We operate with a flat structure: good ideas win - wherever they come from. Questioning assumptions and challenging the status quo isn’t just welcomed, it’s expected. Sustainable pace, long-term ambition Building meaningful technology is a marathon, not a sprint. We believe in balancing focused, ambitious work with a life beyond it. Our hybrid model blends time together in our Shoreditch office with work-from-home days, giving you the flexibility to work sustainably while staying connected in person. And it doesn’t stop there … 🚀 Equity options - share meaningfully in the company you’re helping to build. 🏦 10% employer pension contribution - because investing in future matters. 🍽️ Free office lunches - to keep you energised and focused. 👶 Enhanced parental leave - 3 months full pay paternity and 6 months full pay maternity leave, to provide extra flexibility during the moments that matter most. 🍼 YellowNest nursery scheme - to help working parents manage childcare costs. ☀️ 25 days of Annual Leave (+ Public Holidays) - because taking time to rest matters. 🏥 Private medical insurance - 100% employee cover, giving you complete peace of mind. 💪 Wellhub Subscription - gain access to thousands of gyms, classes and wellness apps, supporting both physical and mental wellbeing. 👀 Eye tests - because good work depends on good health. 📈 Personal development - dedicated support for learning, development, and leveling up over time. 💛 Employee Assistance Programme (EAP) - confidential wellbeing support, available whenever you need it. 🚲 Bike2Work scheme and 🚆 Season ticket loan - to make getting to work easier and greener. 🚗 Octopus EV salary sacrifice - for a simpler, more sustainable way to drive electric. 🔎 Watch this space, we’re continuing to build this as we grow…   We value diversity and are committed to equal employment opportunity regardless of sex, race, religion, ethnicity, nationality, disability, age, sexual orientation or gender identity. We strongly encourage individuals from groups traditionally underrepresented in tech to apply. To help make a change, we sponsor bright women from disadvantaged backgrounds through their university degrees in science and mathematics.    We collect diversity and inclusion data solely for the purpose of monitoring the effectiveness of our equal opportunities policies and ensuring compliance with UK employment and equality legislation. This information is confidential, used only in aggregate form, and will not influence the outcome of your application.

MEET DEEPL DeepL is a global AI product and research company focused on building secure, intelligent solutions to complex business problems. Over 200,000 business customers and millions of individuals across 228 global markets today trust DeepL's Language AI platform for human-like translation, improved writing and real-time voice translation. Founded in 2017 by CEO Jaroslaw “Jarek” Kutylowski, DeepL now has around 1,000 passionate employees and is supported by world-renowned investors including Benchmark, IVP, and Index Ventures. Our goal is to become the global leader in trusted, intelligent AI technology, building products that drive better communication, foster connections, and create a meaningful impact. To achieve this, we need talented people like you to join our journey. If you’re ready to shape the future of AI and grow your career in a fast-moving, purpose-driven environment, DeepL is your next destination. WHAT SETS US APART What sets us apart is our blend of cutting-edge AI technology, meaningful work, and a culture where people truly thrive. We’re a team of innovators, researchers, and creators driven by a shared purpose to unlock human potential by making work simpler, smarter, and more connected. When we share what it’s like to work at DeepL, the reactions are overwhelmingly positive. This might be because of our technology that helps millions of people and businesses communicate and work better every day, or because of the trust, curiosity, and care that shape our culture. What we know for sure is this: being part of DeepL means joining a team dedicated to innovation, growth, and well-being. Discover more about life at DeepL onLinkedIn,Instagram, and our Blog. MEET THE TEAM BEHIND THIS JOURNEY Our Language AI teams form the foundation of DeepL's success. We are a dedicated group of researchers who collaborate closely with engineers, product managers, and designers. Our mission is to build the world's leading language AI system to deliver perfect translations for the most demanding use cases. To that end, we take responsibility for the entire life cycle of the machine learning models that power our language AI products. This includes data, training, quality assurance, and operational aspects. In our highly collaborative teams, each person has the scope to drive impact across the company. YOUR RESPONSIBILITIES We are looking for a Senior Research Scientist to own the foundational modelling decisions behind the next generation of our most capable translation models. This is a high-impact, hands-on role for a researcher who can prototype rapidly, run large-scale experiments, and drive modelling choices all the way into production. In this competitive and highly dynamic field, you will decide which foundation models we build on, which architectures we adopt as we scale, and how we adapt a strong base model into a highly capable translation system working side by side with our post-training, RL, and instruction-following experts. YOU WILL: * Drive the selection and evaluation of open foundation / open-weight models as the basis for our next-generation translation systems. * Lead model selection and general architecture decisions for scaling to hundreds of billions of parameters, including Mixture-of-Experts and other sparse or efficient designs. * Design multi-capability adaptation strategies using LoRA, PEFT, and related methods. * Own the modelling lifecycle for your work: prototyping, ablations, scaling experiments, evaluation, and delivery into production, with rigorous and reproducible evaluation. * Partner closely with post-training, RL/RLHF, and instruction-following specialists to integrate alignment and capability work into the base model. * Stay ahead of the open-model and scaling literature, and bring well-founded recommendations back to the team. QUALITIES WE LOOK FOR * Strong hands-on experience adapting and scaling large language models via fine-tuning, instruction-tuning, or post-training of multi-billion-parameter models beyond black-box use. * Sound judgment about architecture trade-offs at scale (e.g. dense vs. MoE) and about which open-weight foundation models to build on. * Working knowledge of parameter-efficient and multi-capability adaptation (LoRA/PEFT and variants). * A hands-on builder who enjoys training models, running experiments, and debugging pipelines, and who can carry research results through to production with engineering. * Strong coding and experimentation skills (Python, PyTorch/JAX/Tensorflow). * Ability to communicate clearly, collaborate across teams, and align research work with product and engineering priorities. NICE TO HAVE * Experience quantifying uncertainty in large models — calibration and confidence estimation via Bayesian methods, ensembling, steering, or prompt-based approaches. * Experience with machine translation, multilingual NLP, or document-/layout-aware modelling experience. * Familiarity with MoE-specific training and adaptation (e.g. expert routing, Mixture-of-LoRA-Experts) and large-scale data-mixture design. WHAT WE OFFER * Diverse and internationally distributed team: joining our team means becoming part of a large, global community with people of more than 90 nationalities. We're more than just colleagues; we're a group of professionals with a shared mission to connect diverse cultures. Our global presence is growing–we've doubled in size nearly every year, with our employees based in the UK, Germany, the Netherlands, Poland, the US, and Japan, and we continue to expand our network. * Open communication, regular feedback: as a language-focused company, we value the importance of clear, honest communication. We value smooth collaboration, direct and actionable feedback, and believe that leading with empathy and growth mindset makes us better together. * Hybrid work, flexible hours: we offer a hybrid work schedule, with team members coming into the office twice a week. This allows you to engage directly with your team and experience the unique energy of our workspace, while still enjoying the flexibility and comfort of working from home. With flexible working hours and trust in your productivity, we are in sync with your team’s general locations and time zones to foster effective and seamless collaboration. * Virtual Shares - An ownership mindset in every role. We believe everyone should share in our success, and that’s why every employee receives Virtual Shares, linking your contribution directly to DeepL’s growth and rewarding you with a stake in our future. * Regular in-person team events: we bond over vibrant events that are as unique as our team, from local team and business unit gatherings, to new-joiner onboardings, to company-wide events that bring us all together–literally. * Monthly full-day hacking sessions: every month, we have Hack Fridays, where you can spend your time diving into a project you're passionate about and get the opportunity to work with other teams–we value your initiatives, impact, and creativity. * 30 days of annual leave: we value your peace of mind. With 30 days off (excluding public holidays) and access to mental health resources, we make sure you're as strong mentally as you are professionally. * Competitive benefits: just as our team spans the globe, so does our benefits package. We've crafted it to reflect the diversity of our team and tailored it to align with your unique location, to ensure you feel supported every step of the way. If this role and our mission resonate with you, but you're hesitant because you don't check all the boxes, don't let that hold you back. At DeepL, it's all about the value you bring and the growth we can foster together. Go ahead, apply—let's discover your potential together. We can't wait to meet you! WE ARE AN EQUAL OPPORTUNITY EMPLOYER You are welcome at DeepL for who you are - we appreciate authenticity here. Our product is for everyone, and so is our workplace. The more voices we have represented and amplified in our business, the more we will all succeed, contribute, and think forward! So bring us your personal experience, your perspectives, and your background. It’s in our diversity that we will find the power to break down language barriers in the world.