Mechanical Engineer

About the role

The Mechanical Engineer position at Commonwealth Fusion Systems is a critical technical role focused on enabling the rapid scale-up of manufacturing capabilities for fusion power plant construction. In this capacity, you will serve as a key contributor responsible for the mechanical design, analysis, and implementation of all manufacturing equipment and process tooling. Your primary objective will be to own the mechanical integrity of the systems that build our future energy infrastructure. You will translate the high-level requirements of fusion energy production into detailed, actionable mechanical specifications. This involves leading the development of mechanical solutions that ensure the efficient, safe, and reliable assembly of high-energy systems and components. You will act as the technical authority during the commissioning and integration phases, troubleshooting issues and providing expert guidance to ensure all equipment meets stringent performance, safety, and regulatory standards. Furthermore, you will be a driver of continuous improvement, constantly seeking ways to enhance process efficiency, equipment reliability, and overall manufacturing throughput. This role requires meticulous documentation of all engineering decisions and calculations to support future audits, modifications, and long-term operational knowledge. You will also play a mentorship role, guiding junior engineers and technicians on best practices for mechanical integration, testing, and validation procedures.

What you'll do

In this position, you will perform detailed mechanical engineering analysis for new manufacturing equipment and process tooling, ensuring designs are robust and manufacturable. You will develop, iterate, and validate mechanical designs using CAD software to support the buildout of our state-of-the-art production facility. A core responsibility will be to lead the specification, integration, and implementation of mechanical systems within the controlled environments of our cleanroom and manufacturing floors. You will partner directly with the production team to identify and eliminate bottlenecks in equipment layout, workflow optimization, and operational efficiency. The role involves conducting mechanical testing and validation to confirm that all systems meet predefined performance, safety, and reliability criteria before full-scale deployment. You will be the owner of technical documentation, creating and maintaining comprehensive records including detailed engineering drawings, calculations, and assembly instructions. When issues arise, you will lead root cause analysis for mechanical failures and develop and implement corrective actions to prevent recurrence. You will serve as the primary interface with cross-functional stakeholders, ensuring that mechanical solutions are perfectly aligned with project timelines, objectives, and quality targets. This includes evaluating vendor proposals for mechanical equipment and providing critical technical input during procurement decisions to ensure capabilities match our stringent requirements. You will actively implement process improvements designed to increase manufacturing throughput, enhance equipment reliability, and reduce operational risk.

Requirements

To be successful in this role, you must hold a Bachelor's degree in Mechanical Engineering or a closely related technical field. A minimum of five years of progressive, hands-on experience in mechanical engineering roles is mandatory. Candidates must demonstrate extensive, practical experience with mechanical design, analysis, and testing methodologies across multiple projects. Proficiency in CAD software and engineering simulation tools specific to mechanical systems is required for success in this position. A deep understanding of manufacturing processes, production facility engineering, and the constraints of the built environment is essential. You must possess the ability to interpret complex engineering drawings and translate them into precise technical specifications and build instructions. Experience working within a regulated manufacturing or industrial environment is highly valuable given the safety-critical nature of our work. You must exhibit excellent problem-solving skills and the demonstrable ability to troubleshoot and resolve complex mechanical issues independently. Effective communication skills are paramount, as you will need to clearly articulate technical concepts to both technical and non-technical stakeholders at all levels of the organization. You must be authorized to work in the United States without sponsorship at this time. A strict commitment to adhering to all site safety protocols and quality standards is non-negotiable. Willingness to work within the established schedule and location constraints for Devens, MA is required. All candidates must be prepared to pass comprehensive background checks and any required security screenings as part of the hiring process to ensure alignment with our operational needs.

Nice to have

Candidates with prior experience in vacuum systems, cryogenics, or thermal management applications will find their expertise particularly relevant. Familiarity with high-tech manufacturing or semiconductor production environments provides a strong foundation for understanding our operational requirements. Knowledge of automation equipment and mechanical integration techniques is a significant advantage. Experience with statistical process control and the analysis of manufacturing data will enhance your ability to drive improvements. A foundational understanding of project management methodologies and cross-functional team coordination is beneficial for ensuring seamless execution of mechanical projects.

Practical notes

This role is based full-time at our facility in Devens, Massachusetts, requiring onsite presence during standard business hours. Travel is not expected as part of the core responsibilities. This position is initially offered as a contract role with a defined engagement period; however, there is potential for extension based on individual performance and evolving project needs. As emphasized in the requirements section, candidates must be authorized to work in the United States without sponsorship at this time.