Mechanical team lead

At Thorizon, we’re a passionate team of ~ 50 spread across Amsterdam and Lyon, all working together to develop new nuclear power solutions. We design and create frontier technology for Molten Salt Reactors (MSRs).Our purpose is to accelerate the availability of clean energy and help solve the climate crisis.We are in the development phase and progressively solidifying our design through analyses, simulations, experiments, prototyping, and partnerships.Our work requires strong interdisciplinary coupling. This is why we value openness: sharing assumptions, surfacing uncertainties early, and addressing issues directly. In a high-stakes environment, transparency is not a preference but a condition for safety, quality, and trust.We believe safety is both technical and human. Robust designs, validated assumptions, and compliance with codes and standards go hand in hand with an environment where people feel safe to speak up, challenge assumptions, and report issues without fear. Technical performance and human maturity are inseparable, and trust and clarity are essential to succeed.Your missionAre you motivated to provide your expertise and know-how to the ongoing design studies for the Thorizon One reactor? Are you passionate about designing cutting-edge mechanical systems and solving complex engineering challenges? Do you get energized by innovation, and transforming ideas into tangible solutions? Are you a teambuilder that can get the most out of technical experts and specialists, in an innovative and multidisciplinary development environment?You will be the lead and take full responsibility for all activities related to mechanical studies in Thorizon’s reactor design, safety case and validation.You lead the mechanical expertise domain as a coherent and reliable center of excellence, serving the project while continuously adapting to its evolving needs.The primary missions are, on the one hand, to provide comprehensive support and expertise in this area to the system design teams in charge of the reactor design studies and, on the other hand, to define, execute, and adapt where needed the validation program combining experiments, tests, prototyping, either carried out on our own or through shared initiatives, designed to ultimately prove that the innovations in our solution are feasible within the performance, cost, and time constraints of our project.You structure the organization to ensure technical quality, methodological rigor, and effective collaboration, while fostering professional growth and personal responsibility within the team. Within this general framework, you will manage a growing team of junior, intermediate, senior and external mechanical specialists, define an organization designed to ensure the quality and validity of the studies and work performed by your team, and develop this mechanical expertise center in line with the needs of the Thorizon project and its future developments.In your role, you maintain an overview of all design projects carried out within Thorizon (non-nuclear Pilot design, Pioneer nuclear demonstrator design, FOAK/NOAK design), the entire mechanical validation plan, and interfaces with the system design teams and with other areas of expertise (such as materials, chemistry, neutronics and thermohydraulics, as well as nuclear safety). You act as both reference expert and facilitator, helping the project move forward by clarifying priorities, resolving tensions, and enabling sound decision-making.You create an environment where questions, doubts, and alternative viewpoints can be expressed early and constructively, allowing risks to be identified and addressed before they become issues. Your level of expertise allows you to prioritize based on the importance of the needs, and as an expert, you have the power to recommend any necessary actions for the project related to your area of expertise.Furthermore, with your team members, you participate in external networks, including international initiatives, to stay at the forefront of industry developments.In this environment, you get the unique opportunity to put your knowledge to the best use, develop your ideas, explore various aspects of mechanical engineering, how to build and manage an effective expert team, and play a crucial role in the company’s growth.This role is based in Amsterdam, Netherlands or in Lyon, France.In this role you will:Contribute to the development of an effective expert team in mechanics, fulfilling all the needs in this domain for the success of the Thorizon project.Provide comprehensive support and expertise in mechanics to the system design teams, including FOAK/NOAK, Pioneer nuclear demonstrator, as well as non-nuclear Pilot.Define, execute, and adapt where needed the validation program combining experiments, tests, prototyping, designed to ultimately prove that the innovations in our solution are feasible within the performance, cost, and time constraints of our project.Ensure the adequate knowledge and application of relevant Codes and Standards in Mechanics for the development of the project.Ensure the adequate knowledge and application of relevant Computational Tools in Mechanics for the development of the project.Manage, organize and develop the mechanical engineering team, ensuring the quality and validity of the studies and work performed by the team and making the specialists develop their full potential.Support team members’ professional development by identifying and providing opportunities for training and growth.Ensure seamless interfaces and relationships with the System Design Teams, with the other Functional Teams, with the Licensing and Safety Team and with the Management Team.Encourage a culture where individuals take responsibility for their contributions, raise concerns early, and actively participate in finding solutions.Foster a working environment where people feel safe to speak up on safety, quality, or feasibility issues.Support the professional development of team members through feedback, coaching, and learning opportunities.Participate in meetings with regulators with the aim of defending in-house positions and contribute to maintaining an active dialogue with regulators (in particular ASNR, ANVS and FANC).Participate in specifying, selecting, and managing external contractors and suppliers that support the project.Be involved in various international initiatives (IAEA, Euratom…) dedicated to mechanic discipline applied to nuclear projects.Stay updated on industry trends and advancements in approaches, methodologies, Codes & Standards, Computational Tools in mechanics.Your Technical Experience:Master's degree and proven experience in mechanical engineering (10 - 15 years).Strong understanding of solid mechanics, creep, fracture mechanics, and metallic alloy fatigue principles.Experience with system engineering approaches is a plus.Good knowledge and proven application of Codes and Standards and regulations (RCC-MRx, ASME, ESPN…).Good knowledge in computational tool applications.Good knowledge of structural and thermos-mechanical analyses methods, design by rules and quality assurance, which you combine with a practical approach, supporting realization.Good knowledge of materials strategy for innovative nuclear applications, including testing, qualification and manufacturability.Experience in projects including pressure vessels, pipings, large components, mechanical handling.You have at least 5 years of experience managing an expert team in a multidisciplinary technology development environment.As a person :You organize work in a way that makes priorities, interfaces, and responsibilities clear, with a strong attention to quality, traceability, and reliability.You exercise sound judgement: you think strategically within your domain, consider the full system and project context, and take responsibility for prioritising what truly matters.You value diversity of backgrounds, expertise, and perspectives, and you adapt your leadership style to the situation and the people involved in order to strengthen collective effectiveness.You communicate openly and respectfully: you listen before reacting, express yourself clearly and concisely, remain calm under pressure, and write with precision. You work fluently in English, and preferably also in French or Dutch, spoken and written.You approach complexity with curiosity and pragmatism: you rethink problems to find robust, workable solutions, reduce unnecessary complexity, and contribute constructively to progress.You demonstrate a learning mindset: you welcome challenges, question assumptions, and continuously develop your own capabilities and those of the team.You create impact through dependable, high-quality outputs that others can rely on and use as reference.You lead by example: through your behaviour and decisions, you build trust, reinforce standards, and enable others to perform safely and at their best.You contribute to a positive and engaging work environment: you bring energy, humour, and perspective, and you know that shared moments of lightness help teams stay connected, resilient, and effective under pressure.What can you expect from us?A responsible and meaningful mission: contributing to a technology with concrete societal value - reducing carbon emissions and nuclear waste streams - where people can clearly see how their work creates impact beyond the organisation itself.An ambitious and open team of nuclear technology professionals, committed to addressing today’s energy challenges together - in a culture that aims to be blame-free and solution-oriented, while acknowledging that learning and improvement are ongoing.A unifying experience in a fast-growing, VC-backed deep-tech start-up, where collaboration across disciplines is essential and where values are lived, discussed, and continuously strengthened.A fair and transparent reward framework, including a competitive salary and an employee profit-sharing plan, reflecting shared responsibility, contribution, and long-term value creation.An international working environment that values diversity of cultures and perspectives, encourages openness, and builds mutual understanding over time.A stable and accessible work setting, with offices in the heart of Amsterdam or Lyon, next to the central station, supporting sustainable commuting, presence, and day-to-day balance.At Thorizon, technical excellence is inseparable from how we work together. We expect high standards, clear responsibilities, open dialogue, and a shared commitment to safety. This role is for a leader who finds energy in building both robust systems and strong teams.Does this sound like a match? We are looking forward to your application : hr@thorizon.comThorizon takes responsibility to make our company more inclusive. We believe diversity of perspectives strengthens both our technology and our teams, and we want everyone to feel welcome and able to contribute fully. #J-18808-Ljbffr