The Mechanical Commissioning Lead is responsible for the mechanical commissioning scope from design review through Integrated Systems Testing (IST) and final turnover. This role provides accountability to the Commissioning Authority and Commissioning Manager for mechanical system readiness, testing, documentation, and issue resolution across chilled water, condenser water, heat rejection, air handling, room cooling, ventilation, pressurization, BMS controls, fuel oil, and applicable plumbing and process water systems. The position directs mechanical commissioning engineers and technicians while coordinating mechanical contractors, controls integrators, TAB firms, and OEM representatives throughout the commissioning lifecycle.