Established in 1972, Space Applications Centre (SAC), ISRO, has spearheaded India’s journey in space technology. From designing payloads for Chandrayaan-1 and Mars Orbiter Mission to developing communication transponders for INSAT and GSAT series, SAC’s contributions span across navigation, remote sensing, Earth observation, and scientific exploration. SAC’s software engineering practices represent a delicate balance between tradition and innovation. By adhering to stringent quality standards, embracing new technologies, and nurturing a mission-critical mindset, SAC equips its software with the resilience and capability needed to navigate the unforgiving frontier of space. Looking ahead, continuous refinement of these practices will be crucial to ensure India’s continued success in space exploration and successful delivery of space-enabled applications for societal benefit. This talk delves into the software engineering practices employed at SAC, highlighting the unique challenges, innovative methods, and critical approaches undertaken to ensure the highest standards of reliability and quality in mission-critical domain.