CircleCI Concepts

CircleCI is a CI/CD platform built around pipelines, workflows, jobs, and reusable configuration.

Core Ideas

• A pipeline is the full execution triggered by a commit or API event.
• A workflow coordinates jobs.
• A job runs in an isolated execution environment.
• A step is one command or action inside a job.

Key Features

• Orbs for reusable config.
• Workspaces for moving files between jobs.
• Artifacts for storing build outputs.
• Caching for speeding up repeated dependency downloads.
• Executors for defining the runtime environment.

Example Mental Model

1. Trigger a pipeline.
2. Run a workflow.
3. Execute jobs in the correct order.
4. Pass artifacts or workspace contents to later jobs.

Practical Notes

• Use config-as-code through .circleci/config.yml.
• Keep jobs short and focused.
• Use orbs when the same logic repeats across projects.