Beyond Boolean: Solving Hard Problems in Feature Flag Architecture at Scale

As feature flags move from simple toggles to core infrastructure, engineers face complex technical challenges that aren't covered in basic tutorials. This technical session dives deep into 3 critical problems in feature flag architecture at scale: maintaining consistency across regional deployments, handling circular dependencies between flags, and managing flag evaluation performance under heavy load. The presentation walks through specific architectural patterns, including: * Implementing consistent hashing for user targeting across distributed services * Using dependency graphs to detect and prevent circular feature flag references * Building efficient caching layers that handle rapid flag updates without sacrificing evaluation performance * Managing flag cleanup through automated detection of stale references Each pattern will be demonstrated with code examples showing both naive implementations and production-ready solutions.