You said you'd remove that flag after launch. You lied. It's been six months and the flag is still in appsettings.json, the if statement is still in your controller, and nobody remembers which state is "on." This is how codebases turn into haunted houses.
Why Cleanup Matters
Dead feature flags are technical debt with teeth. They add branches to your code that nobody tests. They confuse new developers who don't know the history. They inflate configuration files and make deployments harder to reason about. And they compound.
Every flag you don't clean up makes the next cleanup harder because the cognitive load of understanding the system keeps increasing. The cost of removing a flag is lowest immediately after the feature ships, while everyone still remembers what the thing does. Six months later? Good luck.
Track Every Flag
