Hi, I work on the Squarespace dev platform. It's true that certain blocks still use YUI, but this is system functionality that's not part of our public API. In

Hi, I work on the Squarespace dev platform. It's true that certain blocks still use YUI, but this is system functionality that's not part of our public API. In new templates, a Squarespace developer won't see or touch YUI code. We're no longer creating new features with YUI. We write new frontend editor functionality with modern libraries like React.