Maestro: The Orchestration Language Powering Shopify Flow - Shopify

What this post added

This post introduces Maestro, a new domain-specific orchestration language designed to decouple the Shopify Flow editor and execution engine. Maestro focuses on coordinating function calls and managing execution state durably through checkpoints, enabling at-least-once execution semantics. It defines types and functions, with primitive expressions binding to host language code. The post details how Maestro types and functions are used to model Flow's triggers, conditions, and actions, and how workflow validation is achieved by composing Maestro orchestrations.