Senior Mechanical Engineer, Equipment

Lydian is developing the lowest cost sustainable fuels from waste CO2, water, and renewable electricity to decarbonize the aviation industry. Our breakthrough technology replaces oil and gas refining with fully electrified, modular, and flexible reactor systems that produce fuel with 95% lower emissions than traditional jet fuel.

Since our founding in 2021, Lydian has achieved key milestones in record time, including the production of our first liquid fuel from our pilot system. Lydian is backed by the world's top energy transition investors including Congruent Ventures, Galvanize Climate Solutions, Union Square Ventures, Voyager Ventures, Grok Ventures, and more. We have also earned support from the US Department of Energy, the Defense Advanced Research Projects Agency (DARPA), and have been recognized by Forbes 30u30 and by Silicon Valley Bank's 50 by 2050 List which recognizes the top fifty energy transition companies based on potential impact and scale.

We are seeking a Senior Mechanical Engineer to design and build the lab- and pilot-scale systems that enable rapid technology development.

This role is highly hands-on and development-focused. You will design and construct custom test stands, experimental platforms, and small-to-mid-scale process systems that support core R&D and pilot programs. While the role may occasionally involve contributing to larger skid-based systems, the primary focus is enabling fast, high-quality experimental work through well-designed mechanical infrastructure.

You will work closely with process engineers, materials scientists, controls engineers, and technicians to translate testing needs into reliable, safe, and adaptable hardware.

This role is ideal for someone who enjoys building custom equipment, thrives in experimental environments, and takes pride in creating systems that accelerate learning.

• Design and build custom lab and pilot systems — translate test objectives and process requirements into mechanical designs for experimental platforms and development rigs

• Develop custom test stands — design fixtures, reactors, enclosures, flow systems, and supporting hardware for rapid iteration and materials/process evaluation

• Execute the build process — source components, coordinate fabrication, assemble systems, and support integration in collaboration with technicians and vendors

• Design for flexibility and iteration — ensure systems are modular, reconfigurable, instrumented appropriately, and built to evolve as experiments change

• Support pilot-scale equipment development — contribute to skid-based or containerized systems as programs scale, ensuring alignment with lab learnings

• Collaborate cross-functionally — work closely with process, controls, and R&D teams to ensure systems meet testing, safety, and operational requirements

• Apply safety and compliance best practices — design systems appropriate for pressure, temperature, and chemical environments

• Support commissioning and troubleshooting — participate in startup, debugging, modifications, and performance improvements of new systems

• BS or MS in Mechanical Engineering, Chemical Engineering, Systems Engineering, or related field

• 5+ years of experience designing and building mechanical systems, preferably in lab, pilot, or R&D environments

• Demonstrated experience designing and assembling: custom test stands, experimental platforms, small process systems, first-of-a-kind hardware

• Strong hands-on experience with fabrication methods, component sourcing, and system integration

• Proficiency in 3D CAD (e.g., SolidWorks, Inventor, or similar) and drawing generation

• Strong understanding of:

  • Fluid systems and piping layouts

  • Structural design and supports

  • Materials selection for chemical and thermal environments

• Experience working with technicians, machine shops, and external fabricators

• Alignment with our mission, vision, and virtues

• Challenging, collaborative, and meaningful work and an important voice in company development

• Competitive salary commensurate with experience

• Meaningful equity compensation

• Unlimited PTO and expectation that all employees take significant time off to rest, recharge, and enjoy life outside work

• Excellent insurance with 100% of healthcare, vision, and dental premiums covered for the employee, and 80% coverage for dependents

• 401(k) with company match