abstract_feature_branch is one of the simplest and most minimalistic “Feature Flags” ruby/rails gems out there. It enables you to get started very quickly by simply leveraging YAML files without having to set up a data store if you do not need it (albeit, you also have the option to use Redis as a very fast in-memory data store).

https://andymaleh.blogspot.com/2022/12/abstract-feature-branch-132-redis.html