At Relativity Space, the success of our Terran R vehicle operations relies on software systems that are robust, well-integrated, and rigorously tested. The Software Systems Engineering team is a multidisciplinary function responsible for ensuring that the integrated software system that supports vehicle operations is functional, scalable, performant, and ready for test and launch activities in alignment with the program schedule and risk posture. We bridge the gap between vehicle software, ground systems, and hardware teams to ensure reliable end-to-end system functionality. Our focus includes system-level requirements development, safety engineering and analysis, software-hardware integration, risk management, system-level debugging, launch-readiness verification, and operations support. We play a critical role in mission success by ensuring all software components work seamlessly across the full stack-from control centers to the vehicle in flight.