Exploring CHAOS: Building a Backend for Server-Driven UI Jonathan Baird, Software Engineer; Xin Shen, Software Engineer Jul 8, 2025 A little while ago, we published a blog post on CHAOS:...

Yelp's platform is a central hub for consumers and businesses, offering insights into local businesses, user reviews, and recommendations. Through articles, guides, and user-generated content, Yelp offers insights into discovering restaurants, shops, and services in various locations. Readers can learn about reading and writing reviews, finding popular businesses, and exploring local communities to make informed decisions about where to eat, shop, or visit.

Yelp Engineering

Yelp's CHAOS framework enables server-driven UI by using a GraphQL API that routes requests to backend services which construct UI configurations. The system uses Python dataclasses to define reusable components and actions, supports parallel feature loading for performance, includes error handling to prevent single feature failures from breaking entire views, and offers advanced features like view flows for navigation sequences and view placeholders for asynchronous content loading.