[jkodumal]

For temporary feature flags, we try to clean up as soon as possible. As part of the rollout plan for a new feature, we'll have defined what metrics we're trying to achieve, and once we're confident that we've met those marks, we clean up the flag.

We eagerly create "cleanup branches" and corresponding pull requests to remove a flag-- that front-loads the cleanup work and means we aren't context switching back to try and remember how to clean up a flag.

Also, we've found that in practice flags are usually independent-- testing permutations of flags shouldn't typically be necessary. People usually take an analogous shortcut with feature branches-- we test branches in isolation but don't usually re-test after merging.

[pkaeding]

If anyone is interested, I wrote a blog post detailing the cleanup branch approach: http://blog.launchdarkly.com/how-to-use-feature-flags-withou...