Lld
Low-Level Design
Medium
Distributed Feature Flag & Targeting Evaluator
Design the client-side logic for a Feature Flag system. The system receives a 'ToggleConfiguration' from a remote server. It must evaluate whether a feature is 'ON' for a specific 'UserContext' based on attributes like 'region', 'email_hash' (for percentage rollouts), and 'beta_group'. Evaluation must be near-instant and happen locally in memory. The system must support 'OverrideRules' for internal testing and 'DefaultFallbacks' if the configuration is missing.
Key concepts
strategy patternsingleton patterncaching
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