Reusable workflows

Avoid copy-pasting workflow YAML across repos. Reusable workflows are called via workflow_call:

# .github/workflows/deploy.yml (in a shared repo)
on:
  workflow_call:
    inputs:
      environment:
        type: string
        required: true

# Calling workflow
jobs:
  deploy:
    uses: my-org/shared-workflows/.github/workflows/deploy.yml@main
    with:
      environment: production

Composite actions also help — combine multiple steps into a single action you can reuse across workflows.