Principal Mechanical Design Engineer
CV-LibraryStevenage, HertfordshirepermanentPosted: 4 March 2026
Apply NowCopello is supporting one of its Defence clients in their search for Principal Mechanical Design Engineers.
The roles are available across all areas of the Product Life Cycle, from mechanical future concepts and detailed design through qualification, production, and in-service support.
In these roles of responsibility, you will lead the development of mechanical solutions for a wide variety of complex systems, working closely with multi-disciplinary teams across engineering, manufacturing, quality, and supply chain. You will be expected to provide technical leadership, drive design maturity, and act as a key interface with internal and external stakeholders.
Dynamic (Hybrid) Working: An average of 2–3 days per week on-site dependent on work classification
Security Clearance: British or a Dual UK national with British citizenship.
What we’re looking for from you:
* Ideally Degree, HND, or HNC in Mechanical Engineering (or equivalent) with significant industry experience
* Proven ability to lead mechanical design work packages within multi-disciplinary teams
* Strong experience across full product life cycles, from concept to in-service support
* In-depth knowledge of design proving and qualification activities
* Robust hands-on experience with design methodologies such as DFMEA, DFA, and DFM
* Strong communication skills with the ability to influence, negotiate, and make technical decisions
* Experience engaging with and developing suppliers and external partners
* Ability to manage priorities, assess risk, and mentor less experienced engineers
* Understanding of structural, thermal, and/or dynamic analysis (advantageous)
* Relevant 3D CAD/CAE experience (training provided on company tools)
The roles are available across all areas of the Product Life Cycle, from mechanical future concepts and detailed design through qualification, production, and in-service support.
In these roles of responsibility, you will lead the development of mechanical solutions for a wide variety of complex systems, working closely with multi-disciplinary teams across engineering, manufacturing, quality, and supply chain. You will be expected to provide technical leadership, drive design maturity, and act as a key interface with internal and external stakeholders.
Dynamic (Hybrid) Working: An average of 2–3 days per week on-site dependent on work classification
Security Clearance: British or a Dual UK national with British citizenship.
What we’re looking for from you:
* Ideally Degree, HND, or HNC in Mechanical Engineering (or equivalent) with significant industry experience
* Proven ability to lead mechanical design work packages within multi-disciplinary teams
* Strong experience across full product life cycles, from concept to in-service support
* In-depth knowledge of design proving and qualification activities
* Robust hands-on experience with design methodologies such as DFMEA, DFA, and DFM
* Strong communication skills with the ability to influence, negotiate, and make technical decisions
* Experience engaging with and developing suppliers and external partners
* Ability to manage priorities, assess risk, and mentor less experienced engineers
* Understanding of structural, thermal, and/or dynamic analysis (advantageous)
* Relevant 3D CAD/CAE experience (training provided on company tools)