Edge Config is an ultra-low latency data store for configuration data that is globally distributed on Vercel's Edge Network, allowing near-instant reads of configuration data from various applications and services. It uses a push-based Content Delivery Network (CDN) architecture to replicate data to all regions before it's requested, providing always-available and instant access to configuration data. The system is optimized for fast, inexpensive reads and infrequent writes, with most lookups returning in 5 ms or less and 99% of reads under 15 ms. It's designed to support A/B testing, feature flags, complex redirects, request blocking rules, and rapid experimentation, offering improved performance and reduced layout shifts. The Edge Config API allows for quick queries and retrieval of configuration values, making it easy to integrate with various applications and services.