What do you use for feature flags?

I can guarantee that your codebase is spaghetti of conditional functionality that no developer understands, and that most of those conditionals are leftovers that are no longer needed, but nobody dares to remove.

Feature flags are a good idea, but they require a lot of discipline and maintenance. In practice, they tend to be overused, and provide more negatives than positives. They're a complement, but certainly not a replacement for VCS branches, especially in monorepos.