Senior Mechanical Engineer Equity at Seed-stage synthetic fuel startup

Job Title

Senior Mechanical Engineer

£70k-£90k + Equity

Seed-stage synthetic fuel startup decarbonising heavy industry through first-principles hardware engineering

You will own the end-to-end design and manufacture of critical hardware sub-systems, including reactors and electrolysers. Tasked with making synthetic fuel cheaper than fossil fuels, you will rethink low-volume technologies for mass production. This role involves everything from concept generation and CAD to hands‑on fabrication and commissioning in our London workshop.

London, UK

• Radical engineering freedom to rethink complex systems from first principles, stripping away complexity to achieve ultra‑low‑cost mass manufacturing.
• Extraordinary team culture of hands‑on builders, featuring engineers from elite motorsports, rocketry clubs, and world‑class institutions like Imperial and Cambridge.
• Unique relocation and housing benefits, including a £6,000 annual subsidy to live near the HQ, ensuring you are at the heart of the action.

• Lead the architecture and technical requirement capture for major sub-systems like DAC modules or high-pressure electrolyser stacks.
• Design and execute rapid, low-cost test rigs to validate underlying physical hypotheses and iterate hardware based on real-world data.
• Manage the full lifecycle from Solid Works CAD models and workshop fabrication to the final assembly, integration, and commissioning of fuel plants.

• Has 5+ years of professional mechanical or aerospace engineering experience with a proven track record of delivering complex hardware systems.
• Possesses deep expertise in Solid Works and DFM/DFA, complemented by hands‑on workshop experience in fabrication, welding, or prototype assembly.
• Demonstrates strong fundamentals in thermofluids, heat transfer, and simulation tools like Python, FEA, or CFD to solve high-stakes engineering problems.