My story of when bad feature flag hygiene resulted in a real technical problem is when our Redis kicked over one day. We had good monitoring so it was easy to i

My story of when bad feature flag hygiene resulted in a real technical problem is when our Redis kicked over one day. We had good monitoring so it was easy to identify the problem: network was saturated at 1 GB/s. I traced the problem back to the fact that we had 100+ feature flags that were fully launched, but still loaded into the backend when "all feature flags" were loaded for a team. The way this was implemented returned all team IDs that had the feature flag, and the way this was done had some flags with multiple thousand IDs in them. So 100+ flags, many with 2000+ int entries. We ended up quickly shipping some code to mark features GA, so they wouldn't be loaded from Redis. Cut usage by 99% instantly.