Cleaning up stale feature flags

This skill guides you through finding feature flags that no longer serve a purpose and removing them safely. The ordering is fixed: clean up the code, wait for that cleanup to deploy, and only then change the flag in PostHog.

When to use this skill

• The user asks to clean up, audit, review, or remove their feature flags
• The user wants to find flags that are stale, unused, or fully rolled out
• The user asks "which feature flags can I remove?" or similar
• The user wants to reduce tech debt from old feature flags

Do not activate for an unrelated coding task that merely mentions a feature flag. Cleaning up a flag is its own job, requested by the user.

What makes a flag stale

A feature flag is considered stale when it's no longer doing useful work. PostHog tracks this with two signals: