Principal Mechanical Design Engineer

Our client, a trusted partner to the UK Ministry of Defence, is seeking an accomplished Principal Mechanical Design Engineer to support the design, development, and validation of advanced actuator and control systems. This is a unique opportunity to join Europes leading missile systems organisation, working within a highly collaborative, multi‑disciplinary environment. You will contribute to cutting‑edge mechanical innovation, shaping robust solutions that meet today's operational demands and tomorrow's technological challenges.

• Contribute to mechanical design, development, and proving activities within a multi‑disciplinary team, supporting both prime and variant products, including individual components and assemblies.
• Collaborate closely with manufacturing teams to investigate and resolve production issues, non‑conformances, and defects, ensuring effective design for manufacture and assembly.
• Provide engineering support to functional and environmental testing, including participation in qualification activities and trials.
• Interface with suppliers and purchasing teams to address technical queries and support efficient procurement and supply chain alignment.
• Plan, manage, and report on day‑to‑day engineering activities, ensuring delivery in line with project schedules and key milestones.
• Support the clarification and generation of technical requirements, constructively challenging unnecessary specifications to reduce lead time, unit production cost (UPC), and design complexity.

• Proven experience using Creo (3D CAD) for mechanical design and development.
• Broad engineering knowledge across manufacturing processes, DFMA, tolerance analysis, mass properties, and material selection.
• Experience in structural design, tooling and fixture design, and environmental sealing solutions.
• Familiarity with environmental testing, industrial validation, and product lifecycle management from concept to production.
• Practical application of FMEA, design assurance, and formal design review processes.
• Working knowledge of Defence Standards and regulated engineering environments.
• Strong collaborator within multi‑disciplinary engineering teams, with the ability to lead or contribute to technical design reviews and interface effectively across engineering domains.

Upon submission of your application, should it meet our selection criteria, you will be contacted via e‑mail by one of our talent acquisition specialists to arrange a screening call. This telephone chat is structured to explore a series of questions aimed at matching your competencies and capabilities to the specific demands of the position. Please note, this screening is contingent upon the initial success of your application.

British Citizen or a Dual UK national with British citizenship.

Restrictions and/or limitations relating to nationality and/or rights to work may apply. As a minimum and after offer stage, all successful candidates will need to undergo HMG Basic Personnel Security Standard checks (BPSS), which are managed by our clients Security Team.

For more than 70 years, our client has been in a strong partnership with the UK military. They have accomplished numerous milestones in defence engineering and have provided essential defence capabilities to meet the requirements of the armed forces across land, sea, and air.

This role is based at our client's headquarters in Stevenage, a key location for missile operations. The site offers excellent transportation links, an onsite gym, and a coffee shop. Training and development opportunities are available to all employees.