GitHub Actions
Overview
GitHub Actions automates checks, builds, and deployments in response to repository events.
Why It Matters
It is often the simplest place to automate the workflows a team repeats the most.
Core Concepts
- Workflows respond to events.
- Jobs and steps organize work.
- Secrets and permissions must be managed carefully.
Mental Models
Treat workflows like production code: simple, observable, and safe.
Best Practices
- Keep workflows focused.
- Use caching where it helps.
- Pin permissions tightly.
Common Mistakes
- Putting too much logic in one workflow.
- Ignoring action version drift.
- Leaking secrets or over-permitting jobs.
Trade-offs
Automation saves time, but each new workflow adds maintenance and security surface area.
Decision Framework
| Workflow | Good use |
|---|---|
| PR checks | Validation |
| Main branch | Build and deploy |
| Scheduled | Maintenance and audits |
Examples
- Run tests on pull requests and deploy on main after verification.
Checklists
- Are permissions minimal?
- Are secrets protected?
- Is the workflow easy to debug?
Senior Engineer Notes
Senior engineers keep CI workflows boring and trustworthy. Hidden complexity in automation tends to surface at the worst time.