What Is a Pull Request and How Does the PR Workflow Work?

A pull request (PR) is a request to merge changes from one branch into another, usually into main or another protected branch. It is the central review and approval step in collaborative development: instead of pushing straight to the shared branch, you propose your changes, others review them, automated checks run, and only then does the code merge. This matters most on teams or open-source projects where more than one person touches the same codebase, and where unreviewed changes to the default branch can break everyone.

The problem a pull request solves

Without a PR step, anyone can push directly to the shared branch. That makes it easy to:

• Introduce bugs or broken builds that block the whole team.
• Merge changes nobody reviewed or understood.
• Lose the reasoning behind a change once it is buried in commit history.

A PR turns "here is my code" into a reviewable, discussable, and testable proposal. It creates a record of what changed, why, who approved it, and whether it passed checks before it landed.

The PR lifecycle, step by step

1. Create a branch

You branch off the target branch (for example, main) and make your changes there. The branch isolates your work until it is ready.

Input: a starting point (the current main). Action: create a branch, commit your changes. Expected result: your work exists separately and does not affect main.

2. Open the pull request

You open a PR from your branch into the target branch. This is where you describe the change: what it does, why, and anything reviewers should know.

Expected result: the PR exists as a proposal, and reviewers can be requested.

3. Review

Reviewers read the diff, leave comments, ask questions, and either approve or request changes. Review mechanics typically include:

• Comments on specific lines or the PR as a whole.
• Approvals signaling the change is acceptable.
• Requested changes blocking merge until addressed.

A single PR may go through several rounds of comment → fix → re-review.

4. Automated checks (CI/CD)

Most projects run automated checks on every PR. These usually include tests, linters, and builds. A failing check blocks merge until it passes. This is the mechanism that catches problems before they reach the shared branch.

5. Merge

Once reviews are approved and checks pass, the PR is merged into the target branch. Some teams allow one-click merge once all conditions are met.

Where PRs commonly fail

The "stale review" problem is a workflow bottleneck rather than a code problem: the PR is technically fine, but nobody has looked at it. This is the gap that notification tools aim to close.

Why notifications matter in the PR workflow

A PR only moves as fast as its reviewers respond. When review requests, comments, approvals, and CI failures are buried in a shared channel or an inbox, PRs sit for days. Tools like GitNotifier send these events as Slack DMs instead of channel noise — review requests, comments you can reply to from Slack, approvals, and CI/CD failure alerts, plus a scheduled digest of PRs waiting for your review. The point is not the tool itself but the mechanic: surfacing the right PR event to the right person at the right time shortens the review loop.

Key takeaways

• A pull request is a proposal to merge one branch into another, gated by review and checks.
• The lifecycle is: branch → open PR → review → CI/CD checks → merge.
• Reviews use comments, approvals, and requested changes; checks block merge when they fail.
• The most common blockers are merge conflicts, failing checks, and slow reviews.
• Notifications help mainly with the slow-review bottleneck, not with code correctness.