Git

1. Overview

What it is: Distributed version control — the backbone of code review and CI triggers.

When to use: Always for code and IaC.

When NOT to: Store large binaries/secrets (use LFS/artifact stores; secret managers).

2. Concepts

• Commits, branches, remotes, tags
• Merge vs rebase; fast-forward
• Protected branches; CODEOWNERS
• Hooks (pre-commit) for lint/secrets
• Signed commits/tags (GPG/SSH)
• Bisect for regressions

3. Architecture

graph LR
  Dev1 --> Feature
  Dev2 --> Feature
  Feature --> PR[Pull Request]
  PR --> Main
  Main --> Tag[Release Tag]
  Tag --> CI

4. Production Best Practices

• Small PRs; meaningful messages (Conventional Commits)
• Protect main; required reviews + CI
• Tag releases; changelog automation
• Never force-push shared main; coordinate force-with-lease on personal branches only
• Pre-commit secret scanning

5. Common Mistakes

Mistake	Fix
Commit .env	Rotate; purge history carefully (BFG/filter-repo)
Huge binary in git	Git LFS or artifact repo
Rewrite published history casually	Coordinate; prefer revert

6. Debugging Guide

git status; git log --oneline --graph -20
git bisect start; git bisect bad; git bisect good <sha>
git reflog   # recover lost commits

7. Security

• Signed commits for release tags
• Branch protection; dismiss stale reviews
• Scan history for secrets on schedule

8. Performance

• Shallow clones in CI (--depth); sparse checkout monorepos
• Partial clone filters

9. Real Production Example

Trunk-based; short feature branches; squash merge; semver tags trigger release workflow; CODEOWNERS for /infra.

10. Interview Questions

Beginner: clone vs pull? merge vs rebase?

Intermediate: What is reflog? When reset --hard?

Senior: Recover from leaked secret in history. Monorepo branching strategy.

11. Checklist

• Branch protection
• Commit hygiene + hooks
• Tags for releases
• No secrets in history

12. Cheat Sheet

Command	Purpose
git switch -c feat/x	New branch
git rebase origin/main	Update branch
git revert <sha>	Safe undo on main
git tag -a v1.2.3	Annotated tag

Branch protection (typical)

• Require PR reviews (1–2) + status checks
• Disallow force push to main
• Require linear history or allow squash merges deliberately
• Restrict who can push tags / create releases

Revert vs reset

• revert — safe on shared branches; adds undoing commit
• reset --hard — only on local unpublished commits (or with team coordination)

Related Skills

• github-actions
• cicd
• security

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Author & maintainer: Shanmukha Kumar Karra
Created and maintained as part of AgentOps Kit.