Location: Derbyshire- Onsite (Visa Sponsorship not available) About the Role Are you a hands-on design leader with a passion for solving complex engineering challenges? We’re seeking an accomplished Principal Mechanical Design Engineer and a Senior Design Engineer to take ownership of the design and delivery of advanced mechanical and engine subsystems — from early concept through to production and beyond. In this pivotal role, you’ll lead projects that span across diesel and hydrogen, propulsion technologies. You’ll join a technically driven, collaborative team where engineering rigour meets real-world impact — and where your ideas, leadership, and design expertise will directly influence the future of clean and efficient propulsion. What You’ll Do * Lead and own mechanical design activities across full lifecycle programmes — from concept creation and analysis through validation and launch. * Design, develop, and integrate complex systems and components, such as crankcases, cylinder heads, housings, valvetrain, lubrication, or cooling systems. * Champion engineering excellence, applying first principles to solve challenging problems with creativity and precision. * Collaborate with multidisciplinary teams including analysis, test, manufacturing, and suppliers to deliver optimised, production-ready solutions. * Guide and mentor engineers, sharing your experience to develop capability and ensure technical quality across projects. * Drive continuous improvement, embedding lessons learned into new technologies, tools, and processes. * Influence design strategy for future propulsion systems and contribute to the evolution of sustainable power solutions. What You’ll Bring * A degree in Mechanical Engineering (or related discipline) with a strong background in mechanical design and product development. * Proven experience designing and delivering engine components, subsystems, or relevant powertrain systems across any of the following sectors: automotive, aerospace, off-highway, marine, or power generation. * Strong 3D CAD capability (preferably Siemens NX) and a detailed understanding of GD&T, tolerance stacks, and design calculations (e.g., for bearings, bolted joints, camshaft, and belt drive systems). * Knowledge of FEA, CFD, or thermal/structural analysis tools, and how simulation informs design optimisation. * Experience leading design reviews, technical decisions, and mentoring engineers, with a proven record of delivery across the product lifecycle. * A proactive approach to innovation, sustainability, and the application of sound engineering judgement Why Join You’ll be part of a forward-thinking engineering environment that blends hands-on design with strategic influence. This is an opportunity to: * Work on technically challenging, cross-sector propulsion projects. * Lead design activities that contribute to sustainable, high-performance technologies. * Collaborate with a diverse network of engineers and innovators. * Shape the next generation of propulsion and power systems. If you’re ready to lead from the front — combining mechanical design excellence with systems-level insight — this is the role where you can truly make your mark