What are code reviews and how they actually save time

Key Takeaways

• Code reviews are peer evaluations of code changes that improve quality, share knowledge, and reduce bottlenecks.

• Reviews catch logic errors, ensure test coverage, and promote consistent coding standards.

• They foster team learning, better estimates, and resilience by decentralizing expertise.

• Integrate code reviews into your workflow to enhance collaboration, maintain quality, and increase velocity.

Code reviews are peer evaluations of code changes, typically before those changes are merged into a main branch or released. A reviewer looks at what was written, why it was written that way, and whether it holds up against the team's shared standards.

Done well, code reviews help teams catch issues earlier, improve long-term maintainability, and spread knowledge across the codebase so no single person becomes a bottleneck. 

They also support faster delivery by surfacing problems when they're still cheap to fix. Keep reading to learn how to build a code review process that helps software development teams ship better and faster.

What are code reviews?

A code review happens when one or more developers examine a proposed change before it’s accepted into the main codebase. This usually occurs via a pull request or merge request, though teams also use pair reviews or tool-assisted workflows, depending on their setup.

During a review, the reviewer considers questions like: 

• Are there any obvious logic errors in the code?

• Looking at the requirements, are all cases fully implemented?

• Are the new automated tests sufficient for the new code? Do existing automated tests need to be rewritten to account for changes in the code?

• Does the new code conform to existing style guidelines?

Code reviews should integrate with a team’s existing process. For example, if a team is using task branching workflows, initiate a code review after all the code has been written and automated tests have been run and passed–but before the code is merged upstream.

This ensures the code reviewer’s time is spent checking for things machines miss, and prevents poor coding decisions from polluting the main line of development.

How the code review process works in 5 steps

Code reviews are most effective when they follow a consistent process. Without one, reviews become inconsistent, feedback gets buried, and teams lose the compounding benefits that come from doing this well over time. 

Here's a straightforward approach that works across most team setups:

Step 1: Create a focused branch or pull request

Code reviews usually begin when a developer packages a focused set of changes for review. Smaller, single-purpose changes are significantly easier to review than large, mixed ones.

The more focused the change, the faster and more thorough the review tends to be.

Step 2: Run automated checks before review

Automated tests, builds, linting, and security scans should run before a human ever looks at the code. This lets reviewers focus on logic, maintainability, context, and tradeoffs—the judgment calls that automation can't make.

Step 3: Review the code against shared criteria

Reviewers should use consistent criteria across every review. That includes correctness, test coverage, edge cases, security, performance, readability, and maintainability.

Shared criteria reduce subjectivity and make feedback easier to act on.

Step 4: Discuss feedback and make revisions

Code review is a conversation. Reviewers should ask clear questions, separate blocking feedback from non-blocking suggestions, and explain the reasoning behind requested changes. 

A comment like "this could break under load" is more useful than "change this."

Step 5: Approve, merge, and track follow-up work

Once comments are resolved, the team can approve and merge the change. Any follow-up work should become a trackable task rather than getting buried in review comments.

Jira makes this straightforward by connecting work items with related branches, commits, builds, and pull requests in one place.

Why code reviews matter for agile and DevOps teams

Code reviews support both quality and flow. They're not a checkpoint that slows teams down — they're one of the more reliable ways to keep the software development lifecycle running smoothly as a codebase grows.

Here's what teams consistently gain from them:

What to look for in a code review

Consistent reviews require consistent criteria. Without a shared sense of what matters, feedback varies too much from reviewer to reviewer, and authors don't know what to expect. 

These are the areas worth examining on every review:

• Correctness: Does the code do what it's supposed to do? Are there logic errors, off-by-one mistakes, or conditions that aren't handled?

• Requirements: Are all cases from the spec or ticket fully implemented? Are there edge cases the author may have missed?

• Tests: Are there sufficient automated tests for the new code? Do existing tests need to be updated to account for the change?

• Security: Does the code introduce any vulnerabilities? Are inputs validated, permissions checked, and sensitive data handled appropriately?

• Performance: Are there any obvious performance concerns—unnecessary queries, inefficient loops, unscaled data handling?

• Maintainability: Is the code readable? Could another developer understand it six months from now without extensive context?

• Error handling: Are errors caught and handled gracefully? Does the code fail in a predictable, recoverable way?

• Observability: Is the code instrumented well enough to debug in production? Are the right things being logged?

• Documentation: Are complex sections commented? Does any public-facing API or interface need updated documentation?

Code review best practices

Code reviews only work as well as the process around them. A few consistent practices make a meaningful difference in whether teams get compounding value from reviews or just go through the motions. 

Here are the practices that tend to matter most:

Share the load

At Atlassian, many teams require two reviews of any code before it's checked into the code base. Sound like a lot of overhead?

Really, it's not.

When an author selects reviewers, they cast a wide net across the team. Any two engineers can give input.

This decentralizes the process so that no one is a bottleneck, and ensures good coverage for code review across the team.

Review before merging

Requiring code review before merging upstream ensures that no code gets in unreviewed. Which means that the questionable architectural decisions made at 2 a.m. and the improper use of a factory pattern by the intern are caught before they have a chance to make a lasting (and regrettable) impact on your application.

This is also where bug triage efforts compound. Catching a bug in review is far cheaper than catching it after software release or software deployment.

Use automation for repeatable checks

Style, formatting, builds, tests, and security scans should be automated whenever possible. Human reviewers bring judgment, context, and experience to a review.

That time is better spent on architecture, maintainability, and intent than on catching a missing semicolon. Continuous integration pipelines are a natural place to run these checks automatically before code ever reaches a reviewer.

Build a code review process that helps teams move faster

Code reviews are most effective when teams keep changes focused, define shared standards, automate repeatable checks, and connect review feedback to the rest of the development workflow.

Jira and Bitbucket help teams do exactly that. They connect work items, pull requests, review feedback, test results, and release visibility in one place. 

And for teams working asynchronously or across time zones, Loom makes it easier to leave video feedback on complex changes when a comment alone doesn't capture the full picture. 

Code reviews: Frequently asked questions

Why are code reviews important for software teams?

Code reviews help catch bugs and errors early, ensure code consistency, and maintain high-quality standards. They also foster knowledge sharing and help onboard new team members by exposing them to different parts of the codebase.

How do code reviews improve code quality and team collaboration?

By having multiple developers review code, teams can identify potential issues, suggest improvements, and share best practices. This collaborative process leads to cleaner, more maintainable code and encourages open communication among team members.

Which best practices should teams follow during code reviews?

Teams should provide constructive, specific feedback, focus on the code rather than the coder, and review small, manageable changes. Using checklists and automated tools can help ensure consistency and thoroughness in every review.

How can teams handle disagreements or feedback during code reviews?

Teams should approach disagreements with respect and openness, focusing on the shared goal of improving the product. Discussing feedback in person or via video call can help resolve misunderstandings, and documenting decisions ensures clarity for future reference.