Git — Version Control

Imagine writing an ITR for a client, making changes over three weeks, and then the client says "go back to the version from two Wednesdays ago." Without a history system, you are searching through email threads and old file copies labelled ITR_final_v3_ACTUALLY_FINAL.xlsx.

Git solves this. Permanently.

What Git Is

Git is a version control system — a tool that tracks every change you make to your code, who made it, when, and why.

Every time you save a meaningful checkpoint, you create a commit: a snapshot of your entire project at that moment. Git keeps every commit, forever. You can:

• Go back to any past commit
• Compare what changed between two commits
• Work on a new feature in isolation (a branch) and merge it in when it is ready
• See who changed which line and when (git blame)

The CA analogy: Git is like having a complete, timestamped audit trail of every change to every document in your firm — automatically, forever. Not just the latest version, but every version, with notes on why each change was made.

The Three Concepts That Matter

1. The Repository (repo)

Your project folder, tracked by Git. Run git init once, and Git starts watching.

2. The Commit

A saved snapshot with a message:

git add src/app/fees-page.tsx
git commit -m "add overdue fee highlighting to fees table"

Now that change is recorded with a timestamp and message. Permanently.

3. The Branch

A parallel version of your project where you try something without touching the main code:

git checkout -b add-payment-receipts
# make changes, test them
git merge add-payment-receipts   # bring them into main when ready

If the feature breaks something, you discard the branch. Main is untouched.

Why Git Matters Before Claude Code

When Claude Code writes code for you (Session 4), it will modify files — sometimes many at once. Git is what lets you:

• Review what changed before accepting it
• Roll back if the change broke something
• Keep a clean history of what you (and Claude Code) built and why

A developer without Git is like a CA without work papers. You might produce the right answer, but there is no audit trail and no way to undo a mistake.

Hands-On: Your First Commit

In VS Code's integrated terminal:

# Create a test folder and initialise git
mkdir my-first-repo
cd my-first-repo
git init
 
# Create a file
echo "# My First Project" > README.md
 
# Stage and commit
git add README.md
git commit -m "initial commit"
 
# View the history
git log --oneline

You should see one line: your commit with its short ID and message. That is your first entry in a history that never expires.