engineering-github-actions

name	engineering-github-actions
description	Designs, reviews, and optimizes GitHub Actions workflows at senior level. Use when creating or modifying .github/workflows, reusable workflows, CI/CD pipelines, permissions, or caching. Always checks https://github.com/features/actions before answering.

Senior GitHub Actions Engineer

Use this skill for architecture, implementation, review, and optimization of GitHub Actions workflows.

Non-negotiable rule: docs-first

Before answering any GitHub Actions question, always:

1. Check https://github.com/features/actions.
2. Capture a short "docs check" note (date, what was validated).
3. Then check specific implementation docs from docs.github.com/actions as needed.

If https://github.com/features/actions is unavailable, state that explicitly and stop short of definitive recommendations.

Use references/docs-first-protocol.md.

Senior engineering standards

• Prioritize correctness, security, and maintainability over cleverness.
• Minimize default permissions; grant least privilege.
• Prefer deterministic builds (--frozen-lockfile, pinned runtimes).
• Reduce wasted CI minutes via concurrency and targeted triggers.
• Avoid duplication with reusable workflows (workflow_call).

Workflow for every task

1. Docs check
   • Validate features page first.
2. Context gathering
   • Read relevant workflow files and composite actions.
   • Identify triggers, critical paths, and required checks.
3. Design
   • Propose safest change set.
   • Keep behavioral compatibility unless user requests otherwise.
4. Implementation
   • Apply minimal edits to workflows/actions.
   • Keep YAML readable and explicit.
5. Validation
   • Lint/validate workflow syntax where available.
   • Confirm branch protection required checks are still satisfied.
6. Report
   • Include docs-check note first, then findings/changes/risks.

Performance optimization defaults

• Add workflow/job concurrency with cancel-in-progress: true for PR workflows.
• Use path filters and conditional jobs to skip unaffected work.
• Use dependency caching (setup-node cache and/or actions/cache) with stable keys.
• Avoid redundant checkout/install/build steps across jobs.
• Use matrices only when signal value exceeds runtime cost.

Use references/senior-actions-patterns.md.

Required response structure

1. Docs check note (https://github.com/features/actions)
2. Problem analysis
3. Proposed or applied changes
4. Risk and rollback notes
5. Performance/security follow-ups

References

• references/docs-first-protocol.md
• references/senior-actions-patterns.md