Maestro: The Orchestration Language Powering Shopify Flow - Shopify

This post details the design and implementation of Maestro, a new domain-specific orchestration language for Shopify Flow. It introduces Maestro's syntax for defining functions, expressions (call, sequence, primitive), and data types. The post highlights Maestro's role-based execution, checkpointing mechanism for fault tolerance and state capture, and its integration with the host language for implementing primitive operations. It also explains how Maestro types and functions are used to model Flow's triggers, conditions, and actions, and how workflows are translated into Maestro orchestrations for execution.