Job Description Your future team: Join a leading Nuclear Engineering company that pioneers innovative engineering solutions across complex projects. With a reputation for technical excellence and a commitment to safety, we offer a dynamic environment where your expertise will make a real impact. If you're looking to take on a technically challenging and rewarding role in a collaborative and forward-thinking company, we want to hear from you. Your missions: As a Principal Mechanical Engineer, you will be at the forefront of delivering cutting-edge engineering solutions, from initial concept to implementation. You will provide technical leadership, oversee project deliverables, and ensure compliance with relevant regulations and quality standards. Day to day responsibilities will include: Leading and delivering engineering solutions from optioneering through to implementation. Manage budgets, timelines, and resources effectively. Oversee testing and commissioning processes. Collaborate with cross-disciplinary teams, integrating safety and engineering disciplines. Provide guidance and tasking to junior engineers and designers, offering subject matter expertise. Lead packages of work and support project managers with performance tracking. Ensure compliance with relevant industry standards, including BS EN 13001, BS 2573, and BS EN 13155. Why join the community of Switchers? As one of the Top 3 Nuclear Engineering companies in the world, Assystem offer a competitive benefits package which includes: 25 days of annual leave bank holidays 8% company pension contributions Healthcare cash-plan to get money back on dental, medical, physical care Employee assistance programme including 24/7 access to free mental health support, virtual gym classes and more Get professional and industry membership fees paid for.