Do you have an entrepreneurial spirit and a passion for engineering? Do you love designing and implementing complex electrical systems?  Are you looking for a company that is constantly trying to push the boundaries of what it means to offer a better construction solution process by using design/build?  If the answer is, “Yes!” then we have an opportunity that will excite you. Who are we? We are ARCO, a Family of Construction Companies.

ARCO/Murray Engineering is seeking a Senior Mechanical Engineer to join our Mission Critical Engineering team in Downers Grove, Illinois. In this role, you will lead the full mechanical scope for hyperscale, colocation, and enterprise data center projects, guiding the development of complex cooling and mechanical infrastructure systems essential to high-availability facilities.

You will join an established but rapidly growing design/build group focused on delivering reliable, scalable, and efficient data center solutions. Our team collaborates closely with internal construction partners, project managers, and commissioning teams—working together to deliver world-class mission-critical environments.

We are dedicated to the well-being of our associates and are proud to be consistently recognized as a Best Place to Work. Our compensation and benefits package not only supports our associates and their families but benefits local communities and communities around the world.

• Industry-leading performance-based bonus program
• Employee Stock Ownership Plan (ESOP)
• Traditional and Roth 401k
• Tuition reimbursement for associates
• Scholarship for associates’ children up to $28,000 per child
• 1-month paid sabbatical after every five years of employment, plus $5,000 for travel
• 1-week paid volunteer leave each year
• 100% charitable match
• Medical, dental, and vision insurance coverage
• Paid parental leave

At ARCO, our first core value is to treat people fairly and do the right thing. We are committed to building and sustaining a culture that supports diversity and inclusion. We are proud to be an equal opportunity employer, and all qualified applicants will receive consideration for employment.

From recruiting, training, and hiring practices to selecting our subcontractors, we understand that diversity of all those involved in the construction process enhances our ability to deliver the best solutions to our customers. We hire the best and the brightest from across the country – constructing a team of experts in architecture, design, engineering, project management, and business services. 

• Lead the mechanical design process for mission-critical data centers, including chilled water systems, DX systems, CRAH/CRAC, heat rejection, and white-space cooling.
• Guide system development from early concept and basis-of-design through construction documentation, commissioning, and turnover.
• Apply ASHRAE TC 9.9 guidance and critical environment standards to ensure reliability and efficiency.
• Perform cooling load calculations, CFD coordination, and mechanical equipment sizing.
• Coordinate with electrical, controls, and architectural teams to ensure system integration supporting N, N+1, and 2N redundancy.
• Generate design and construction documents using Revit and AutoCAD.
• Support construction by reviewing RFIs, submittals, and field conditions.

• 7–20 years of mechanical engineering experience with data centers or mission-critical systems
• Bachelor’s degree in Mechanical Engineering, Architectural Engineering, or related field
• Proficiency with Revit and AutoCAD
• Strong understanding of critical cooling systems and redundancy strategies
• Ability to manage multiple fast-paced projects
• Experience in design/build is a plus

• Willingness to travel to project sites as required (e.g., 10-30%).
• Familiarity with engineering deliverables in a GC setting (i.e., design-build or EPC support) is a plus.

We are proud to be one of the fastest-growing, privately-owned companies in America, celebrating over 30 years of experience as design-build experts. We have completed over 6,300 design-build projects across 48 states and 48 major cities nationwide. We ranked #4 out of the top 100 design-build companies in the U.S. and #17 on ENR's Top 400 Contractors list of 2024.

Most importantly, our clients like us, trust us and want to do business with us. We are looking for people with the same enthusiasm, passion, and respect for the hard work that brought us to where we are today. Are you a person that can make a difference at ARCO? If the answer is, “Yes!” we look forward to meeting you.

ARCO does not accept unsolicited resumes from individual recruiters or third-party recruiting agencies without pre-approval from ARCO’s Human Resource team. Pre-approval is required before any external candidate can be submitted. ARCO will not be responsible for fees related to unsolicited resumes and for candidates who are sent directly to our hiring managers.

EOE, including disability/vets