Our client, a leading organisation in the Defence and Security sector, is currently seeking a Principal Engineer (Mechanical SME) to join their team. This is a permanent position focusing on technical excellence, problem-solving, and technical review, ensuring mechanical engineering standards, designs, and decisions support business performance, safety, and innovation.Key Responsibilities:Act as the recognised Subject Matter Expert (SME) for all mechanical engineering mattersProvide high-level technical guidance across multiple projects and programmesLead complex problem-solving and root cause analysis for critical engineering issuesReview and approve mechanical designs, calculations, and technical documentationAssist in defining, maintaining, and improving mechanical engineering standards, processes, and best practicesSupport design reviews, risk assessments, and engineering assurance activitiesProvide expert input during bids, proposals, and project planningMentor and coach engineers to build mechanical engineering capability across the businessJob Requirements:Extensive experience in mechanical engineering within a relevant industry (e.g. defence, engineering, manufacturing)Proven track record of solving complex engineering challengesDeep technical expertise in mechanical design, analysis, and materialsStrong understanding of engineering standards, compliance, and safety requirementsExcellent problem-solving and analytical skillsStrong communication skills, able to transla