GitHub employs feature flags as a strategic tool to enhance deployment efficiency and mitigate risks, allowing them to introduce new features and improvements while maintaining service continuity. By isolating potentially risky changes behind feature flags, they can enable or disable these features swiftly, ensuring minimal disruption in case of issues. This approach not only reduces deployment risks but also facilitates the incremental development of new features, enabling staff to work on small, manageable batches and avoid long-lived feature branches. The use of feature flags allows for thorough testing in various environments and supports different shipping strategies, such as enabling features for specific user groups or a percentage of users, which helps gather feedback and validate implementations before full-scale deployment. Despite the additional planning, coordination, and technical debt associated with this approach, GitHub finds that the advantages, including easier code reviews and faster, more confident shipping, significantly outweigh the costs.