The Kong Gateway's routing system, crucial for traffic handling and security, underwent significant enhancements in its 3.0 version update, transitioning to a Rust-based Expressions Router that offers increased efficiency and performance with a 75% reduction in routing construction time when processing up to 10,000 rules. This update introduced a concise Domain Specific Language (DSL) for defining routing rules, leveraging the pest library from the Rust ecosystem, and allowing complex routing requirements to be addressed with fewer rules. The system prioritizes routes based on likelihood, optimizing checks to improve efficiency, and includes condition-triggered partial route reconstruction to further reduce time consumption. The 3.7 version added migration support for transitioning from traditional JSON-based routes to Expressions routes, enabling users to run both types concurrently with comprehensive GUI support for a seamless transition. Additionally, a shared codebase between frontend and backend, using WebAssembly and Rust, allows for interactive features and ensures consistent behavior between the browser and Gateway during proxying.