[rco8786]

Yes, that's the general idea - and it works pretty well.

It can also be a huge PITA. The fallacy is that a "feature" is an isolated chunk of code. You just wrap that in a thing that says "if feature is on, do the code!". But in reality, a single feature often touches numerous different code points, potentially across multiple codebases and services/APIs. So you have to intertwine that feature flag all over the place. Then write tests that test for each scenario (do the right thing when the feature is off, do the right thing then the feature is on). Then you have to remember to go back and clean up all that code when the feature is on for everyone and stabilized.

It's a good tool, but it's not an easy tool like a lot of folks think it is.

[zimzam]

In web development there is often a single place you can put a feature flag though.

For example maybe the feature flag just shows/hides a new button on the UI. The rest of the code like the new backend endpoint and the new database column are "live" (not behind any flags) and just invisible to a regular user since they will never hit that code without the button.

As far as "remembering" to clean up the feature flag, teams I've been on have added a ticket for cleaning up the feature flag(s) as part of the project, so this work doesn't get lost in the shuffle. (And also to make visible to Product and other teams that there is some work there to clean up)