GitHub Actions Interview Guide

🟢 Easy (Basics)

1. Workflow?

YAML triggered by events (push/PR/schedule).

2. Runner?

Machine executing jobs (hosted/self‑hosted).

3. Jobs/steps?

Jobs have steps (shell or actions).

4. Artifacts/cache?

Persist files; speed builds with cache.

5. Secrets & vars?

Store securely; pass as env/inputs.

1. Matrix?

Run across versions/OS combinations.

2. Reusable workflows?

workflow_call for DRY across repos.

3. Environments?

Gates & approvals for prod deploys.

4. OIDC cloud auth?

Short‑lived tokens without stored creds.

5. Concurrency?

Cancel in‑progress runs for same ref.

1. Security?

Pin by SHA, least‑privilege, dependabot, secret scanning.

2. Scaling?

Path filters, composite actions, artifact reuse.

1. Need prod approval.

Use environments with required reviewers.

2. Long flaky builds.

Tune cache keys; split jobs; retry on failure.

3. Secret sprawl.

Org‑level secrets + reusable workflows; prefer OIDC.

Generated for quick interview revision — basics, hands-on, advanced, and scenarios.