Principal Mechanical Engineer High-Performance Defence & Autonomous Systems | £70k | North East England A fast-growing, high-technology engineering business is looking for a Principal Mechanical Engineer to lead the design of advanced electro-optical and autonomous systems used in real-world defence and security environments. This is a hands-on leadership role for a senior mechanical engineer who wants to build cutting-edge products that actually get deployed — not just designed. You’ll take full ownership of complex products from concept to production, working alongside elite electronics and software teams to deliver systems that track, identify and counter airborne threats in real time. Why this role stands out This isn’t consultancy or incremental engineering. You’ll be designing mission-critical hardware that protects real people, sites and infrastructure. You’ll get: Direct ownership of product design from CAD → prototype → deployment Influence over engineering standards, tools and design culture The chance to mentor and shape a growing engineering team Visibility and impact in a company where decisions are made quickly If you enjoy solving hard mechanical problems and seeing your work used in the field, this is the kind of role engineers wait years for. What you’ll be doing Leading the mechanical design of high-performance electro-mechanical systems Owning new product development from concept through verification and release Improving existing products for quality, cost and manufacturability Producing and maintaining detailed CAD, drawings, calculations, BOMs and test data Setting and enforcing engineering standards and best practice Mentoring and technically guiding other mechanical engineers Working closely with electronics, software and systems teams You’ll be expected to be both technically hands-on and a design authority for the mechanical function. What they’re looking for Degree in Mechanical Engineering (2:1 or higher) Strong background in complex product design and development Advanced 3D CAD experience (Inventor preferred) FEA experience (Ansys ideal) High attention to detail and structured engineering mindset Comfortable owning designs, making decisions and mentoring others Proven ability to deliver to deadlines in demanding R&D environments What’s on offer £70,000 (depending on experience) Performance-related bonus Flexible working options UK relocation support 25 days holiday bank holidays (with long-service extras) Private healthcare & life assurance Pension with employer matching EV car scheme Free breakfast A modern, high-energy engineering environment in a beautiful rural location A collaborative culture where engineers are trusted and empowered Important You must have the right to work in the UK Visa sponsorship is not available If you’re a senior mechanical engineer who wants to work on seriously impressive technology with real-world impact, this is one of the most exciting roles in the UK engineering market right now.