This document discusses building a decoupled Drupal site architecture using JSON:API, ReactJS, and Elasticsearch. It defines decoupled Drupal as exposing Drupal data via web services for consumption by other applications. Key points covered include advantages of decoupling like content syndication and frontend developer experience. JSON:API and GraphQL are presented as options for the Drupal API. ReactJS is recommended for building client-side applications. Elasticsearch is proposed for site search. Performance tuning and caching strategies are also addressed.