Harness Feature Management & Experimentation (FME) introduces "Large Segments" to enhance feature management at an enterprise scale, addressing challenges that traditional feature flagging tools and homegrown solutions face in handling vast user bases. This capability allows enterprises to efficiently manage targeted feature rollouts for millions of users, ensuring precision, control, and security without the complexities of managing extensive user lists manually. Large Segments offer benefits such as faster rollouts, improved application performance, large-scale experimentation, consistent user experiences, and enhanced governance and security. This innovation empowers enterprises, especially those in regulated industries, to conduct seamless phased rollouts and experiments with robust A/B testing and compliance controls, providing a powerful tool for managing digital initiatives at an unprecedented scale.