Job Description At Assystem, we’re driving forward some of the UK’s most complex and high-profile Nuclear Defence programmes – and we’re looking for a Principal Project Manager (PPM) who’s ready to take the lead. This is more than project management. It’s about influencing strategic outcomes, shaping capability across the business, and ensuring we deliver mission-critical projects with precision, accountability, and innovation. As a senior leader in our Defence business, you’ll play a pivotal role in managing and evolving a multi-project portfolio, supporting blue-chip defence clients and aligning delivery with AEIL’s wider growth objectives. Your missions: Programme & Portfolio Delivery Oversee a large volume of concurrent projects with full lifecycle responsibility Lead governance reporting on performance metrics – safety, time, cost, quality, client satisfaction Leadership & People Development Inspire, lead, and line manage project and PMO staff, helping them reach their full potential Provide coaching, direction, and mentoring to improve delivery capability across the function Strategic & Commercial Insight Contribute to budget planning, business case development, and financial performance cycles Identify and embed opportunities for innovation and continuous improvement Lead by example in client relationship management and commercial negotiation 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.