GitHub Actions Advanced Patterns#

Once you move past single-file workflows that run npm test on every push, GitHub Actions becomes a platform for building serious CI/CD infrastructure. The features covered here – reusable workflows, composite actions, matrix strategies, OIDC authentication, and caching – are what separate a working pipeline from a production-grade one.

Reusable Workflows#

A reusable workflow is a complete workflow file that other workflows can call like a function. Define it with the workflow_call trigger: