Harness successfully transitioned from its homegrown feature flag solution, Local FeatureFlags, to Harness Feature Flags, effectively managing over 200 feature flags across six environments for more than 4,000 customers while maintaining simplicity for developers. This migration aimed to enhance the power of feature flagging without compromising ease of use, addressing limitations of the previous system which supported only basic boolean flags and required independent management for each environment. The transition followed a phased approach to mitigate risks, involving the use of a Java SDK for Admin APIs, running Harness Feature Flags in audit mode, and implementing an automated synchronization mechanism for new flags. The process included extensive testing and validation to ensure no performance impact, ultimately leading to a successful rollout in production. The transition has improved the feature flag management experience for various stakeholders, including developers, product managers, and QA teams, while maintaining a consistent and simple user experience.