The four-eyes principle is a governance control mechanism requiring at least two individuals to review and approve critical actions in software development, ensuring speed without compromising oversight. This principle is crucial for feature flagging as it mitigates risks associated with unilateral decision-making by mandating peer reviews before implementing changes that could affect system stability, security, compliance, and user experience. While distinct from the segregation of duties, which separates responsibilities, the four-eyes principle involves multiple parties in the approval process, enhancing knowledge transfer and creating audit trails that facilitate compliance and incident analysis. Effective implementation requires defining approval requirements based on risk, setting up role-based access control, enforcing approvals through change requests, building automated audit trails, and integrating these processes into CI/CD pipelines. Avoiding common pitfalls such as self-approvals or a rubber-stamp culture ensures the principle's effectiveness, fostering transparency, accountability, and trust within the organization.