Harness Smart Feature Flags enhance software reliability by enabling controlled feature rollouts, real-time monitoring, and seamless rollbacks, ensuring high velocity and robust performance for a smooth user experience and operational resilience. In a landscape where digital transformation demands reliable software as a cornerstone for growth and customer trust, feature flags provide developers with a strategic toolset that goes beyond simple on/off toggles. By integrating reliability considerations early in the Software Development Life Cycle, developers can release software confidently, manage feature flags with a Git-like experience, and employ automated lifecycle management. The case study of Entur showcases how their deployment frequency increased significantly while reducing failed change rates, thanks to Harness's approach. Site Reliability Engineering (SRE) complements this by fostering a culture of continuous learning and adaptation, with smart feature flags serving as a pivotal component in managing the complexities of fast-paced software delivery environments. By facilitating adaptive deployments, these flags help mitigate potential issues, preserve the integrity of live environments, and enhance user experiences, ultimately leading towards autonomous ecosystems where reliability is seamlessly integrated into the development process.