Senior Mechanical Process Engineer

Amentum is a global leader in advanced engineering and innovative solutions, supporting critical missions across defense, intelligence, energy, and civilian sectors. Our people are our competitive advantage, driven by purpose, collaboration, and a commitment to delivering excellence for our customers and communities. We are seeking a Senior Mechanical Process Engineer to join Amentum’s Advanced Solutions Group. Candidates may be based at either our Tullahoma, TN; Farmington Hills, MI; or Greenville, SC office. Our Advanced Solutions Group delivers the design, construction, and operation of unique and complex research and development facilities across the nuclear, automotive, motorsports, defense, and aerospace industries. Our team has supported an impressive range of clients, including Audi, Boeing, BMW, Fiat Chrysler, Ford, Honda, General Motors, NASA, the U.S. Air Force, U.S. Navy, U.S. Department of Energy, Volkswagen, and organizations throughout North America, Europe, and Asia. Most projects involve unique and complex designs, offering the opportunity to work on a variety of challenging assignments in a dynamic, fast-paced, and collaborative environment. In this role, you will lead and manage projects as part of a multidisciplinary team, taking ownership from concept through execution. We are seeking a Mechanical Process Engineer who is committed to delivering high-quality solutions, ensuring client satisfaction, and successfully executing projects within scope, budget, and schedule. Essential Responsibilities: Lead project teams to develop new designs for various process systems supporting research and test facilities. Take ownership of the technical schedule and budget performance for assigned work. Independently plan, schedule, conduct, and coordinate engineering activities through the selection, adaptation, and modification of appropriate techniques, procedures, and criteria. Analyze project features and scope while applying sound engineering principles and best practices. Review results from assigned tasks and junior engineers to ensure work is complete, accurate, and properly documented. Develop technical reports and presentations for project management teams and clients. Perform formal quality checks of others’ work to ensure completeness and accuracy. Lead, mentor, and provide technical guidance to junior engineers. Collaborate closely with structural, machine design, controls and instrumentation, and aerodynamics/fluid dynamics engineers to support project objectives. Size and specify piping/ducting and related components, and select compressors, pumps, fans, valves, flow measurement, and fluid conditioning equipment. Design process and mechanical systems, including: High-pressure cryogenic and pneumatic piping systems. High-temperature systems, including steam systems. Refrigeration, vacuum, and fuel systems. Specialty HVAC systems and components. Thrive in a fast-paced environment, meeting deadlines while maintaining high-quality standards. Support the Project Manager in ongoing design and engineering efforts. Participate in internal and external meetings, as well as design reviews, with project teams and clients. Gather information, interview stakeholders, conduct studies, perform calculations, and prepare preliminary layouts and sketches as required. Provide installation support and supervision, collaborating with suppliers, subcontractors, and other trades both remotely and at project sites. Create engineering calculations and specifications and oversee the development of engineering drawings. Required Qualifications: US citizenship is required to comply with government customer requirements and/or applicable government regulations. A Bachelor of Science in Mechanical, Aerospace, or a related engineering field from an ABET-accredited program. Minimum 10 Years engineering experience or 12 Years engineering experience and a MS degree from an accredited engineering school. Prior experience designing process systems, including piping and thermal conditioning systems. Self-motivated with the ability to work both independently and collaboratively within a team environment. Demonstrated ability to lead and contribute effectively within a multidisciplinary engineering team. Demonstrated knowledge and experience with both standard and specialized process piping systems. Strong mechanical and process engineering analytical and problem-solving skills. Excellent verbal and written communication skills, with a proactive, team-oriented approach and strong organizational abilities. Experience managing project scope, schedule, and budget for individual engineering projects. Working knowledge of process systems and components, including pumps, valves, heat exchangers, chillers, and rotating equipment. Experience developing process system layouts, engineering drawings, and technical specifications. Site and field installation experience, including troubleshooting and resolving process system issues. Knowledge of ASME B31.1, ASME B31.3, and ASME Boiler & Pressure Vessel (B&PV) Code requirements. Knowledge of thermodynamics, fluid mechanics (compressible and incompressible flow), thermal sciences, and process systems. Experience in the design and/or maintenance of mechanical process systems is preferred. Experience with engineering software such as AutoCAD, 3D modeling software, AutoPIPE, CAESAR II, Mathcad, Creo, and AFT is preferred. Preferred Qualifications: Professional Engineer (PE) license or the ability to obtain licensure. Prior design experience supporting Department of Energy (DOE), Department of Defense (DoD), NASA, nuclear, or test facility projects. Experience working within NQA-1 quality assurance programs and requirements. Current or previous U.S. Security Clearance, including a Q Clearance. Description of Work Environment: Work will mainly be performed in an inside-office environment. Field work may be required, including climbing test stands and working around machinery. Travel may be required to support design reviews, attend factory acceptance testing of equipment, support construction activities, and provide onsite support for startup and commissioning activities. Compensation Details: $120,000 - $155,000 The compensation range or hourly rate listed for this position is provided as a good-faith estimate of what the company intends to offer for this role at the time this posting was issued. Actual compensation may vary based on factors such as job responsibilities, education, experience, skills, internal equity, market data, applicable collective bargaining agreements, and relevant laws. Benefits Overview: Our health and welfare benefits are designed to support you and your priorities. Offerings include: Health, dental, and vision insurance Paid time off and holidays Retirement benefits (including 401(k) matching) Educational reimbursement Parental leave Employee stock purchase plan Tax-saving options Disability and life insurance Pet insurance Note: Benefits may vary based on employment type, location, and applicable agreements. Positions governed by a Collective Bargaining Agreement (CBA), the McNamara-O'Hara Service Contract Act (SCA), or other employment contracts may include different provisions/benefits. Original Posting: 10/21/2026 - Until Filled Amentum anticipates this job requisition will remain open for at least three days, with a closing date no earlier than three days after the original posting. This timeline may change based on business needs. Amentum is proud to be an Equal Opportunity Employer. Our hiring practices provide equal opportunity for employment without regard to race, sex, sexual orientation, pregnancy (including pregnancy, childbirth, breastfeeding, or medical conditions related to pregnancy, childbirth, or breastfeeding), age, ancestry, United States military or veteran status, color, religion, creed, marital or domestic partner status, medical condition, genetic information, national origin, citizenship status, low-income status, or mental or physical disability so long as the essential functions of the job can be performed with or without reasonable accommodation, or any other protected category under federal, state, or local law. Learn more about your rights under Federal laws and supplemental language at Labor Laws Posters ( . #J-18808-Ljbffr