Principal Mechanical Engineer – Complex Systems We are working with a highly innovatiove engineering company seeking a Principal Mechanical Engineer with a proven track record in designing, developing, and delivering complex, multi-component mechanical systems. This is a senior, hands-on role for an engineer who has previously operated at a principal or senior engineering level, combining technical ownership, design leadership, and mentoring responsibilities. This position will lead across the full product lifecycle, including concept development, 3D CAD modelling, assemblies, FEA/structural analysis, prototyping, testing, and production release, while setting engineering standards and supporting the development of other engineers. Key Responsibilities * Lead the end-to-end mechanical design of high-spec, multi-part systems, ensuring solutions are robust, reliable, and manufacturable * Provide technical ownership and direction across projects, including design strategy, risk mitigation, and problem-solving * Mentor and support other mechanical engineers, driving best practice, design reviews, and engineering standards * Produce and maintain high-quality technical documentation, including CAD models, detailed drawings, BOMs, design calculations, and test reports * Collaborate closely with cross-functional teams including electronics, software, and systems engineering to deliver integrated solutions * Balance your own hands-on design work with reviewing and guiding wider project deliverables Essential Experience * Proven experience at a Principal or Senior Mechanical Engineer level, delivering complex, high-spec mechanical systems * Expertise in full lifecycle mechanical engineering from concept, design, FEA/structural analysis, prototyping, testing, and production handover * Strong experience in 3D CAD modelling and assemblies (e.g., Creo, SolidWorks, Catia, Autodesk Inventor) * Experience with PLM systems (Teamcenter, Windchill, or similar) and managing BOMs, drawings, and technical documentation * Knowledge of manufacturing processes, DFMA, tolerance analysis, and design for reliability * Proven track record of mentoring engineers, leading design teams, and setting engineering standards * Hands-on, practical approach with problem-solving, troubleshooting, and innovation in complex mechanical assemblies Desirable * Experience in sectors such as defence, aerospace, offshore, renewable energy, industrial machinery, or high-precision systems * Familiarity with mechanical testing, prototyping, verification, and validation processes * Comfortable delivering results in fast-paced, project-driven environments with tight deadlines and budgets Why Apply This is a rare opportunity to combine technical leadership with hands-on mechanical engineering ownership, shaping the design of complex systems while mentoring other engineers. You will play a key role in taking product to the next level of conception creating a fully tested, operational system