Leidos and its Multi-Domain Solutions (MDS) division are seeking a highly motivated Junior Mechanical Engineer to support the planning, design, and analysis of mechanical systems—primarily Heating, Ventilation, and Air Conditioning (HVAC)—for mission-critical operations across government, commercial, and institutional facilities. This role offers the opportunity to work under the mentorship of senior engineers and contribute to system layout, equipment selection, energy modeling, and construction documentation. The ideal candidate possesses a solid foundation in mechanical engineering principles, a passion for learning, and a commitment to delivering energy-efficient, reliable, and code-compliant designs.