Senior Mechanical Engineer

Limelight Steel is a clean technology company developing an electric ironmaking process that uses laser light to decarbonize primary steel production. Their core innovation replaces traditional carbon-intensive blast furnaces with a laser-based furnace system, enabling the ironmaking process to be fully electrified. The company reports up to 20% energy savings over conventional steelmaking methods and aims to deliver zero-emissions steel at cost-parity with existing production techniques. The company's mission is centered on addressing one of the most carbon-intensive industrial sectors in the global economy. Steel production is responsible for approximately 7-9% of global CO2 emissions, and Limelight Steel's approach targets the primary ironmaking stage, which is the largest source of emissions in the steelmaking value chain. By electrifying this process with laser technology, they seek to enable a scalable, economically competitive pathway to decarbonized steel. Limelight Steel has received significant recognition and institutional support, including a grant from the U.S. Department of Energy's ARPA-E program, backing from Khosla Ventures, and inclusion on the Cleantech Group's 2024 Cleantech 50 to Watch list. The company was also named by Popular Science as one of the 50 greatest innovations of 2024 and appeared on the Forbes 30 Under 30 energy list. They are an Activate Fellowship company, reflecting their origins in deep scientific research.

Position Summary

As a Senior Mechanical Engineer at Limelight Steel, you will design, build, and commission mechanical systems for our Laser Furnace as we scale clean steel production from demonstration to commercial scale. This is a highly hands-on role developing high-temperature, metallurgical process equipment and industrial infrastructure, including:

• thermo-mechanical machine design;

• molten materials handling;

• fluid and gas piping systems; and

• vacuum atmospheres and seals.

Roles & Responsibilities

• Own the design of equipment suitable for use with molten materials, ensuring mechanical integrity and safety at high temperatures.

• Collaborate with pyrometallurgical engineers and subject matter experts to incorporate metals industry best practices into equipment design and implement process improvements.

• Design and implement industrial-scale mechanical infrastructure, including piping networks, cooling systems, gas handling equipment, and plant utilities required to support demonstration plant operation.

• Create detailed CAD models & drawings suitable for fabrication by vendors. Create process flow diagrams, and piping & instrumentation diagrams. (ED + ME)

• Balance speed and rigor in designing, prototyping, building, and testing new equipment for demonstration and scale-up.

• Interface with manufacturers, vendors, machine shops, and contractors to procure, fabricate, and install components while managing fabrication and installation to maintain budget and schedule.

• Provide engineering support during equipment installation, commissioning, and plant operation.

Key Qualifications

• Bachelor’s degree in mechanical engineering or related field.

• 5+ years of industry experience.

• Strong CAD modeling and detailed design skills, including GD&T and weldment design.

• Hands-on experience designing, building, and troubleshooting prototypes and industrial equipment.

• Experience working with process equipment, including systems such as gas handling, vacuum pumps, industrial gas storage and transport, thermal management systems (chillers, heat exchangers, fluid plumbing), and hydraulic & pneumatic systems.

• Strong fundamentals in heat transfer, fluid mechanics, and solid mechanics.

• Strong fundamentals in materials selection and stress analysis for high-temperature operation.

• Experience working with industrial safety standards.

• Demonstrated experience managing multiple vendors and contractors.

• Ability to efficiently think through design problems from first principles.

• Ability to work independently and in team-oriented, fast-paced environments.

Additional Qualifications Desired

• Experience with high-temperature industrial processing equipment (e.g., furnaces, kilns, reactors).

• Experience designing equipment for high-temperature industrial processes (>500°C preferred, molten material handling super preferred).

• Experience designing vacuum-rated equipment and/or pressure vessels (>500°C preferred).

• Experience with thermo-mechanical finite element modeling (e.g., COMSOL, Ansys).

• Experience supporting plant installations or industrial infrastructure projects.

Compensation

Salary range for this role is $160k–$190k plus meaningful equity, depending on experience and level.

Benefits

• Competitive stock option package

• Comprehensive health benefits that include:

  • Full premium coverage for PPO Gold for employees with 80% coverage for dependents

  • Full premium coverage for Vision and Dental for employees

• Generous time-off schedule

  • 20 days paid time off (accrued according to number of hours worked)

  • 10 holidays (personalized to the holidays you observe)

• Sustainable 401(k) retirement savings plan with company match

• 2x weekly catered team lunches

• A team of curious, passionate, kind, and courageous people committed to eliminating industrial emissions that contribute to climate change

• Unparalleled opportunities for growth, leadership, and project ownership in a dynamic and rapidly-growing startup company