Workflows
definitions → runsHow it maps
GitHub Actions → durable executionworkflow file→ definition (the DAG's shape)
workflow run→ run, with real wall-clock timestamps — no virtual clock
job→ parallel task — jobs fan out like the ETL transforms
step→ sequential node inside its job's DAG
conclusion→ terminal state: success / failure / cancelled / skipped
run_attempt→ retry count, shown in the run header
Live shows history, not a live tail — GitHub's API reports completed steps; in-progress steps update when you hit ⟳ refresh. Workers, heartbeats, timers, signals and the chaos panel only exist in the Sandbox.
Event log — the source of truth
Worker pool
☠ Chaos panel
Kill a worker mid-task and watch: heartbeat flatlines → 3 missed beats → task requeued with backoff → another worker replays and resumes.