Senior Multiphase CFD Engineer

About Gridcog Gridcog is a SaaS start-up focused on advancing the clean energy transition. The team brings together energy professionals building project modeling software that helps users make informed, strategic decisions about energy projects. Role Overview This Senior Simulation Engineer (Modeling) position centers on improving and expanding the simulation and optimization capabilities within Gridcog’s Python codebase. The work blends mathematical modeling, numerical methods, and production-level software engineering to deliver accurate, efficient, and reliable simulations at scale. What You Will Do Enhance and extend simulation and optimization features in the core Python platform Work with mathematical models and numerical methods to support complex energy project scenarios Ensure modeling outputs remain accurate and efficient as the platform grows About the Platform The Gridcog platform models the physical and commercial aspects of energy projects. It integrates technologies such as solar, wind, batteries, flexible loads, gensets, and EV fleets, capturing their interactions within electricity markets and tariff structures worldwide. Who Should Apply Simulation engineers with experience in modeling uncertainty and solving complex business problems Candidates with backgrounds in energy systems modeling are encouraged, but those with transferable skills from other modeling or data science domains will also be considered Location This position is based in London, England, United Kingdom.

Join physicsx as a Senior Simulation Data Engineer, where you'll play a critical role in developing and optimizing simulation data workflows. You will collaborate closely with cross-functional teams to enhance our simulation capabilities and ensure data integrity. Your expertise will be instrumental in driving innovation and improving our processes.

About OLIXAt OLIX, we are pioneering the future of AI technology. With the rapid growth of AI outpacing any technology in history, there is a critical infrastructure gap in chip and power station production. Our innovative solution, the Optical Tensor Processing Unit (OTPU), is set to redefine performance and energy efficiency standards, creating unprecedented opportunities in the tech landscape for the coming decades.The Role:We are looking for a passionate and skilled Senior Mechanical Simulation Engineer to spearhead the analysis, simulation, and optimization of precision opto-mechanical systems and advanced substrate structures that are vital for the performance of our OTPUs. This role is perfect for a candidate with extensive experience in advanced simulations focusing on structural response (static and modal), thermal transfer, optical alignment, and fluid flow modeling. You will lead simulation-driven development of precision assemblies and materials that meet our stringent optical, thermal, mechanical, fluid flow, and reliability standards.Collaboration is key in this position. You will work closely with teams across mechanical, optical, electrical, and materials domains to ensure that our designs maintain exceptional stability, thermal performance, and structural integrity throughout manufacturing and operation.

Join Our Team as a Senior Modelling Engineer II!At Runna, we are assembling a dynamic team dedicated to creating the leading training platform for runners worldwide. Our mission is to empower everyday runners to excel by providing an exceptional app that offers top-tier training, coaching, and a supportive community, whether you're aiming to improve your 5k performance or preparing for your first marathon.Our growth has been remarkable! In November 2023, we successfully closed a $6.5 million funding round led by JamJar, with contributions from Eka Ventures, Venrex, and Creator Ventures. In 2024, we were honored to be recognized by Apple as one of the three global finalists for the iPhone App of the Year, showcasing the innovation and impact of our platform. Furthermore, in 2025, we became part of the Strava family!Our ambition is bold: to be the premier global training platform for millions of runners around the globe. As we accelerate our journey with the recent acquisition by Strava, now is an exciting time to become a part of something significant. The Train Team, a cross-functional group of over 35 professionals, is at the core of Runna’s mission: delivering outstanding training experiences to hundreds of thousands of runners globally. We focus on creating and dynamically adjusting optimal, personalized training plans at scale, analyzing performance data for training adjustments, and providing users with valuable insights based on their training and environment.We embrace a flexible hybrid working model, requiring you to be on-site three days a week at our London office.

Join Our Visionary Team at Runna!At Runna, we are on a mission to create the premier training platform for runners. Our innovative app empowers everyday athletes to excel, providing access to top-notch training, expert coaching, and a supportive community whether you're aiming to improve your 5k or preparing for your first marathon.Our rapid growth is fueled by a strong vision, backed by a recent $6.5M funding round led by JamJar and supported by Eka Ventures, Venrex, and Creator Ventures. In 2024, we had the honor of being named one of Apple’s three global finalists for the iPhone app of the year, and in 2025, we proudly became a part of Strava!We aspire to be the leading global training platform for millions of runners. With our recent acquisition by Strava accelerating our growth, this is an exciting time to join us. As part of our dynamic Train Team, which includes over 35 professionals from engineering, product, design, and coaching, you will play a crucial role in delivering exceptional training experiences to hundreds of thousands of runners worldwide. You will engage in developing personalized training plans at scale, analyzing performance data, and providing insights to our users based on their training and environmental conditions.We embrace a flexible hybrid working model, requiring you to be on-site three days a week at our London office.

Waymo is at the forefront of autonomous driving technology, dedicated to becoming the world's most trusted driver. Originally initiated as the Google Self-Driving Car Project in 2009, our team has been relentlessly working to enhance mobility access and save lives by developing the Waymo Driver—The World’s Most Experienced Driver™. With over ten million successful rider-only trips facilitated by our technology, which has driven over 100 million miles on public roads and tens of billions of miles in simulations across more than 15 U.S. states, we are shaping the future of transportation.The Simulation ML Infrastructure team is responsible for creating scalable AI/ML infrastructure that propels our Simulator team towards innovative, state-of-the-art simulations of realistic environments for the Waymo Driver's training and testing. By leveraging large foundation models trained on extensive datasets, we enhance the authenticity and control of our simulations, including realistic representations of vehicles, pedestrians, cyclists, roads, traffic control systems, and weather conditions.We are currently seeking a highly skilled Senior Machine Learning Infrastructure Engineer to spearhead the development of advanced AI/ML infrastructure for multi-billion parameter foundation models tailored for ML accelerator-friendly simulations. Your extensive knowledge in massive model scaling, ML accelerators, and distributed training will be vital in designing and optimizing our systems.

Waymo is a pioneering company in the field of autonomous driving technology, dedicated to becoming the most trusted driver in the world. Originating from the Google Self-Driving Car Project in 2009, Waymo has concentrated on developing the Waymo Driver—The World’s Most Experienced Driver™—to enhance mobility access and save lives lost to traffic accidents. The Waymo Driver supports our fully autonomous ride-hailing service and is adaptable across various vehicle platforms and applications. With over ten million rider-only trips and more than 100 million miles driven autonomously on public roads, complemented by tens of billions of miles in simulation across 15+ U.S. states, our experience is unparalleled.The Simulator team is at the forefront of creating cutting-edge simulations of real-world environments for the training and assessment of the Waymo Driver. We leverage machine learning to accurately model the real world, incorporating realistic agents (vehicles, pedestrians, cyclists, motorcyclists, etc.), road systems, traffic controls, and weather conditions. To enhance the precision and flexibility of our simulations, we utilize large foundation models trained on extensive datasets, enabling rapid setup and deployment of multiple scenarios for our driver.Our London-based team collaborates closely with our colleagues in Mountain View and Oxford to develop and enhance these foundation models and integrate them into various evaluation and training products. We are seeking talented research engineers eager to tackle these innovative challenges.In this hybrid role, you will report directly to an Engineering Manager.

AECOM is seeking a Senior or Principal Civil 3D Modeller to support infrastructure projects in London. This role centers on applying advanced Civil 3D skills to produce accurate models for a range of engineering and construction initiatives. Role overview Work closely with multidisciplinary teams to develop and refine design solutions. The position involves creating detailed models that support project delivery and contribute to effective collaboration across engineering disciplines. What you will do Use Civil 3D to generate and manage models for infrastructure projects Coordinate with colleagues from various specialties to ensure integrated project outcomes Support design innovation and maintain high standards of quality in modelling work Requirements Extensive experience with Civil 3D software Background in infrastructure or related engineering projects Strong collaboration and communication skills

About UsPhysicsX is an innovative deep-tech company at the forefront of numerical physics and Formula One, dedicated to revolutionizing hardware innovation through software acceleration.We are crafting a cutting-edge AI-driven simulation software stack tailored for engineering and manufacturing in advanced industries. Our platform enables high-fidelity, multi-physics simulations via AI inference throughout the entire engineering lifecycle, unlocking unparalleled levels of optimization and automation in design, manufacturing, and operations. We empower engineers to push the boundaries of possibility, serving leading innovators in Aerospace & Defense, Materials, Energy, Semiconductors, and Automotive sectors.The RoleAs part of our product team, PhysicsX is creating a platform utilized by Data Scientists and Simulation Engineers to construct, train, and deploy Deep Physics Models. The backbone of this platform is the management of vast volumes of intricate simulation data, facilitating high-fidelity multi-physics simulations through AI inference.We are seeking a Senior Frontend Software Engineer to join our dedicated team of Frontend Engineers. You will work collaboratively in a cross-functional environment, where you will have the autonomy to influence implementation decisions. You will be responsible for developing and enhancing the frontend that animates our platform — from dynamic 3D visualizations of simulation data to seamless API integrations that enable complex machine learning workflows. You will architect composable frontend structures, optimize performance for data-intensive interfaces, and ensure intuitive interactions for our engineers and scientists handling large datasets and simulation outputs.In this senior role, you will significantly shape the technical direction — authoring Technical Decision Records, mentoring junior engineers, and establishing standards that ensure our platform remains reliable, secure, and efficient. This position is perfect for a creator passionate about delivering exceptional user experiences and building robust frontend architectures.What You Will DoDevelop and improve a frontend platform that supports intricate simulation and machine learning workflows — from 3D visualizations to seamless API integrations and data-heavy interfaces.Design and implement scalable frontend architectures and component systems, including micro-frontend patterns, to facilitate maintainable development.Enhance user experience through advanced caching strategies, performance monitoring, layout optimization, and accessibility best practices.Develop and implement sophisticated state management and data flow patterns to accommodate real-time simulation data and complex user interactions.Take ownership of your work from inception to completion, ensuring high-quality results.

Join Monzo as a Senior Forecasting Modeller, where you will leverage advanced analytics to shape our financial forecasts. Your expertise will guide decision-making processes and enable us to enhance our strategic planning. You will collaborate closely with cross-functional teams to develop robust predictive models that drive business growth and improve operational efficiency.

Join our innovative team at Egis Group as a Senior Wastewater Modeller, where you will play a pivotal role in the design and analysis of wastewater systems. You will leverage advanced modelling techniques to enhance the efficiency and sustainability of our projects. This is an exciting opportunity to work on impactful projects that contribute to environmental sustainability.

Join our innovative team at dev2 as a Senior Data Modeller. In this role, you will be at the forefront of shaping our data architecture and modeling strategies to drive insightful decision-making across the organization. Your expertise will be critical in designing sophisticated data models that enhance our analytical capabilities and support our business objectives.

Launch Your Career with AECOM and Make an Impact!“Join our team of flood risk specialists and help shape the future of the Water Industry!”We are seeking a dedicated Senior Flood Modeller to become a vital part of our expanding Water Business Line in London. This is your opportunity to contribute to high-profile projects throughout the UK and beyond while being part of one of the UK’s leading engineering hubs.As a Senior Flood Modeller at AECOM, you will serve as a key technical resource, mentoring junior staff and driving our service offerings to local authorities, water companies, and both private and public sector clients.Your Responsibilities:Develop and validate hydraulic models using software such as Flood Modeller, TUFLOW, Mike 11, Mike 21, HEC-RAS, and ICM for Flood Alleviation Schemes, Flood Risk Assessments, and reservoir flood studies.Create water quality models utilizing industry-standard software like MIKE, Delft3D, SIMCAT, and/or ICM.Conceptualize and outline modelling strategies, assessing risks and opportunities.Conduct and review hydrological assessments in accordance with the Flood Estimation Handbook, ReFH2, and WINFAP standards.Lead and contribute to tenders for innovative projects and multimillion-pound framework contracts.Mentor team members to enhance their professional growth.Foster strong relationships with clients and collaborate with other technical disciplines.Stay informed about relevant legislation and guidelines impacting our services.Utilize AECOM’s project management systems to deliver exceptional outputs within the agreed timelines and budgets.Work in close partnership with clients and multidisciplinary teams to execute a variety of flood risk management projects.If you are driven by innovation and eager to turn visionary ideas into reality, AECOM is the place for you. Join us in our mission to not just build infrastructure but also uplift communities and enhance lives. Follow our AECOM Water page on LinkedIn to stay updated on the meaningful projects we are engaged in!Grow Your Career with Us!Become a part of our vibrant Water business, which comprises around 700 experts across the UK and Ireland. Collaborate with top-tier engineers and consultants to deliver a range of captivating projects.

Egis Group is seeking a Senior Modeller to join its Water Sector team in London. This role centers on developing and applying advanced modelling techniques for water resource management and infrastructure projects. Key responsibilities Develop and implement advanced models to address water resource and infrastructure challenges. Collaborate with colleagues from different disciplines to deliver solutions that meet client needs. Collaboration The Senior Modeller works alongside professionals from multiple backgrounds, ensuring that modelling approaches align with project goals and client requirements.

Begin your journey with us and thrive in your career.Are you eager to collaborate with a team of skilled modellers dedicated to revolutionizing the water sector?Join our innovative and diverse Water Team as a Senior Wastewater Hydraulic Modeller. You will have the flexibility to work from one of our offices in the UK or Ireland while benefiting from our adaptable hybrid working arrangement.As a vital contributor, you will play an essential role in executing transformative water projects both within the UK and internationally. We are committed to developing significant flood mitigation strategies, enhancing pollution control measures, and advancing infrastructure initiatives. This diversity of projects will be pivotal for your ongoing professional growth. Our unique methodology integrates our modelling team with broader project teams, allowing for close collaboration with experts across various disciplines to devise comprehensive solutions.As a leading authority in Blue-Green infrastructure and nature-based solutions, we partner with both public and private sector clients such as Severn Trent, Anglian Water, Northern Ireland Water, the Environment Agency, LLFAs, and several other infrastructure providers. Our offerings include Flood Risk Assessments, Drainage Strategies, Outline Business Cases, hydraulic models, and detailed designs. We establish industry benchmarks by providing guidance that defines best practices, positioning AECOM at the forefront of the water industry. This role presents a remarkable opportunity to contribute to a talented and diverse team devoted to innovation, teamwork, and efficiency.Your responsibilities will include:Model Development: Construct hydraulic models and validate sewer networks; oversee integrated model development, assist in project scoping and planning, including flow survey validation, and devise catchment-wide strategic solutions addressing flooding and pollution challenges.Technical Expertise: Drive technical innovation through the application of cutting-edge technologies; develop solutions for our clients and create project scopes and tender responses.Reporting: Prepare and present technical reports, presentations, and documentation to effectively communicate modelling outcomes utilizing strong communication skills.Leadership: Mentor and guide team members in their professional development and cultivate positive relationships with clients.Quality Assurance: Review hydraulic models, calculations, and technical reports to ensure adherence to quality standards and compliance with modelling specifications.If you are passionate about innovation and transforming ambitious ideas into reality, AECOM invites you to join us. Be part of a team that not only builds infrastructure but also uplifts communities and enhances lives. Follow our AECOM Water page on LinkedIn for updates on our projects and initiatives.

Join OakNorth, where we are dedicated to empowering the UK’s most ambitious businesses. Since our inception in 2015, we have successfully lent over $18 billion across the UK and US, contributing to the creation of more than 58,000 new homes and 36,000 new jobs, while supporting hundreds of thousands of personal savers, all driving growth in the UK economy.Our lending operations serve as the backbone of our growth strategy, further enhanced by our expanding services in Business Banking and Personal Savings. We are looking for a Senior Fullstack Engineer to lead our digital lending initiatives and quantitative modelling efforts.

Waymo, a pioneer in autonomous driving technology, is dedicated to becoming the world’s most trusted driver. Since its inception as the Google Self-Driving Car Project in 2009, Waymo has been at the forefront of innovation, developing the Waymo Driver—The World’s Most Experienced Driver™—to enhance mobility while significantly reducing the number of lives lost in traffic accidents. The Waymo Driver powers our fully autonomous ride-hailing service and is adaptable to various vehicle platforms and applications. With over ten million rider-only trips completed, fueled by our experience of autonomously driving over 100 million miles on public roads and tens of billions of miles in simulation across more than 15 U.S. states, we are transforming transportation.The Driver Understanding and Evaluation (DUE) team at Waymo is focused on creating comprehensive metrics to evaluate the Waymo Driver’s behavior in real-world scenarios. We are developing advanced technologies such as context and scene analysis to enhance our driving understanding, as well as augmenting real-world driving data to generate rare driving events. This includes building large-scale data infrastructures and improving components like agents and realistic simulators, which are pivotal for our technical strategies and methodologies in assessing the Waymo Driver's performance.The DUE Machine Learning team will develop and maintain scalable machine learning systems and simulation workflows, enhancing evaluation processes and developer onboarding experiences. By merging expert human insights with cutting-edge machine learning models, we will provide training and evaluation data across hundreds of metrics and components that define the Waymo Driver. We are seeking passionate researchers and software engineers eager to harness machine learning techniques to elevate the evaluation systems within our autonomous vehicles, driven by a relentless pursuit of performance improvement.This position reports to the Engineering Manager.

Waymo is at the forefront of autonomous driving technology, striving to become the world's most reliable driver. Originating from the Google Self-Driving Car Project in 2009, Waymo has dedicated itself to developing the Waymo Driver—The World’s Most Experienced Driver™. Our goal is to enhance mobility access while preventing the tragic loss of life caused by traffic accidents. The Waymo Driver powers our fully autonomous ride-hailing service and is adaptable across various vehicle platforms and applications. To date, we've completed over ten million rider-only trips, with extensive experience driving autonomously over 100 million miles on public roads and conducting tens of billions of miles in simulation across more than 15 U.S. states.The Simulator team is responsible for creating cutting-edge simulations that mimic realistic environments to train and test the Waymo driver. Through advanced machine learning techniques, we model real-world scenarios, including realistic agents such as vehicles, pedestrians, cyclists, motorcyclists, and more, alongside roads, traffic systems, and weather conditions. By leveraging large foundation models, trained on our vast datasets, we can rapidly set up and deploy diverse scenarios to challenge our driver.We are excited to establish a team in London, UK, to collaborate with our colleagues in Mountain View and Oxford on enhancing these foundational models and integrating them into various training and evaluation tools. We seek enthusiastic research engineers eager to tackle these groundbreaking challenges.In this hybrid role, you will report directly to an Engineering Director.

CuspAI is an AI-driven company focused on advancing material science. The team brings together recognized leaders in AI, chemistry, and engineering to address challenges in fields such as energy, clean water, computing, and carbon capture. Their work centers on developing a 'search engine' for next-generation materials, aiming to speed up material discovery and deliver real-world impact. As a Scientific Software Engineer specializing in Polymer Simulations, the role centers on building and refining atomistic simulation capabilities for polymer systems. The official title will be 'Member of Technical Staff', reflecting the technical depth of the position. Role overview This position focuses on designing workflows, setting methodologies, and establishing standards for polymer simulations. The work connects atomic-level modeling with the broader material properties that matter in industrial applications. Collaboration with both AI researchers and experimental partners is a key part of the job. What you will do Design and implement atomistic simulation workflows for polymer systems, including polymerization, melt equilibration, and production runs. Introduce and explore simulation techniques beyond molecular dynamics to address complex material challenges. Work with the AI research team to integrate machine learning models into simulation workflows, linking computational, experimental, and AI-driven insights. Collaborate with experimental partners to validate simulation results and strengthen the feedback loop between simulation and experiment.