Checkpoint: Professional Workflow

This checkpoint tests the judgment layer of Git — the part that separates someone who knows commands from someone who can run a professional workflow.

You will write pure functions that model real Git decisions. The sandbox can't run real Git; the reasoning is what we grade: conflict resolution semantics, recovery choices, and conventional-commit tooling.

History is a decision log

Everything in this module reduces to one skill: reading history as the record of decisions and rewriting it deliberately. The checkpoint puts you in the scenarios — the merge conflict, the bad commit on main, the stash you forgot — because muscle memory only forms when the stakes feel real. Get them wrong here; it is the cheapest place to be wrong you will ever get.

Scenarios, not trivia

Notice the shape of these problems: nobody asks you to recite what git rebase does. You are handed a situation — two branches that diverged, a commit that should never have landed, a colleague waiting on your fix — and asked what you actually type. That is how real work arrives, and it is how interviews at serious teams are conducted.

If a scenario trips you, do not memorize the answer. Replay it in a scratch repository: git init in /tmp, create the mess, and solve it with your hands. Ten minutes of that beats an hour of reading, and the muscle memory persists into the next conflict you meet in a real codebase.