Mechanical Design Engineer

📍 London, N4
🏛️ 4 days in our office, 1 day from home (choose from Tue–Thu)
💰 £40 - 50k per annum + equity

About Shellworks

At Shellworks, we’re on a mission to make plastic waste a thing of the past. We’re creating a new generation of materials - sustainable, high-performing, and designed to disappear. By reimagining how materials are made, we’re tackling one of the world’s most urgent environmental challenges.

About the Role

We're seeking a talented Mechanical Design Engineer to help create the next generation of plastic-free products and packaging. In this role, you'll work alongside a cross-functional team of experts in manufacturing, material science, and industrial design to develop non-toxic and compostable solutions to replace single-use plastics. From concept to large-scale production, you'll apply your skills to create new applications for first-of-a-kind materials.

This is a hands-on role for someone who can balance creativity and rigour, moving comfortably between CAD, prototyping, and commercial discussions. You’ll join a small, ambitious engineering team and work closely with our founders, designers, and manufacturing partners to deliver bespoke packaging solutions that customers love - and that help us scale impact.

You’ll play a direct role in driving revenue growth, ensuring our technical capabilities keep pace with expanding sales opportunities and enabling Shellworks to win and deliver even more projects.

Key Responsibilities

As a Mechanical Design Engineer at Shellworks, you’ll:

• Champion product development: Take technical ownership of novel products and packaging solutions from early proof-of-concept through to high-volume production. You will be designing specifically for the unique behaviours of our Vivomer materials, balancing cost, quality, and technical requirements as we scale.

• Engineer products for success: Approach unfamiliar material challenges with precision and detail. You will use robust risk mitigation and validation tools - including first-principles analysis, FMEAs, and Design of Experiments (DoE) - to interrogate, optimise, and confidently validate your designs.

• Drive hands-on prototyping: Translate ideas into physical reality quickly. You will design products, assemblies, fixtures, and jigs in CAD, utilising rapid tooling and prototyping techniques to test assumptions and prove out scalable manufacturing solutions.

• Communicate complex concepts: Act as a technical bridge. You will collaborate closely with a cross-functional team (materials science, manufacturing, industrial design) and external clients, translating complex technical challenges into clear, compelling narratives and visual presentations.

• Scale our engineering capabilities: You will play a key role in implementing engineering best practices, establishing robust documentation, and refining our product development lifecycle to support the rapid expansion of our product portfolio.

Must haves

• Degree in Mechanical Engineering or Design Engineering with 2-4 years of industry experience bringing physical products to market in multidisciplinary environments.

• Strong engineering analysis skills (tolerance analysis, DoE, Moldflow, risk analysis), with an obsessive attention to detail.

• Proficiency in 3D design, CAD and Design for Manufacture, coupled with an extensive hands-on approach to design-make-test engineering.

• Proactive attitude to identifying, mitigating and solving problems across the business with self motivation to learn new skills and contribute in different areas.

• Organised and collaborative in documentation and working style, with excellent communication and presentation skills to both internal and external stakeholders of varying technical backgrounds.

Nice-to-haves

• Experience working with mass-manufacture polymer production techniques and familiarity around industrial equipment

• Keen eye for industrial design and aesthetic requirements of the industries Shellworks works across.

• Experience working with OnShape, Moldflow, Adobe Suite, Figma, and rendering software

• Technical project management experience and commercial fluency

Don’t meet 100% of the qualifications? Studies show that women and people from underrepresented groups often hesitate to apply unless they meet every requirement. At Shellworks, we value diversity of thought and recognise that skills and experience can be built in many ways. If you’re excited about this role and our mission but don’t tick every single box, we’d still love to hear from you.

What we offer

🌴 21 days holiday + birthday off + 27–31st December (plus public holidays)
📚 Growth and development opportunities as we scale
👍 Competitive salary + equity options
🎉 Regular socials + daily catered lunch at the office
🐚 A tight-knit, mission-driven team working on something that matters

Join Us

At Shellworks, you’ll join a team that’s redefining what materials can do — and how design and engineering can help solve global challenges.

If you’re an adaptable product design engineer who loves turning complex problems into elegant, manufacturable solutions, we’d love to hear from you.