What is Code Review?
Code review is the practice of systematically examining proposed source code changes through peer review before they are merged into the main codebase. It catches defects early, improves consistency, spreads knowledge across the team, and raises overall code quality through constructive, human evaluation of every change.
What is code review?
Code review is the practice of having one or more developers examine a proposed change to the code before it is merged into the shared codebase. Typically the author opens a pull request describing the change, and reviewers read the code, ask questions, suggest improvements and check that it meets the team's standards. Only once the change is approved does it merge.
It is a human check that complements automated testing. Where tests verify that code behaves correctly, review evaluates whether it is well-designed, readable and consistent - judgements that tools cannot fully make. The conversation around a change is often as valuable as the approval itself.
Why does code review matter?
Reviewing changes before they merge catches defects when they are cheapest to fix, prevents poor patterns from spreading, and keeps the codebase consistent even as many people contribute. A second set of eyes frequently spots edge cases, security issues or simpler approaches the author missed.
Review also spreads knowledge. When developers read each other's work, no single person becomes the only one who understands a part of the system, which reduces risk and helps new team members learn the codebase quickly. Over time this shared understanding raises the standard of the whole team, because good patterns and lessons are passed on with each review rather than locked inside one developer's head.
What do reviewers look for?
A thorough review goes beyond whether the code works:
- Correctness - does it do what it should, including edge cases?
- Readability - is it clear to someone unfamiliar with it?
- Design - does it fit the architecture and avoid duplication?
- Security - does it introduce any vulnerabilities?
- Tests - is the change covered by meaningful tests?
Code review best practices
Keep changes small, because large pull requests get reviewed superficially. Review promptly so authors are not blocked, and focus comments on the code rather than the person. Automate the mechanical checks - formatting, linting and tests - through a pipeline so reviewers can concentrate on design and logic. Treat review as a two-way conversation aimed at the best outcome, not a gate to defend, and agree shared standards so feedback is consistent.
How PixelForce approaches code review
At PixelForce, code review is a standard part of how our in-house Adelaide team works throughout Phase 2 Development, QA and Release. Every meaningful change is reviewed by another developer before it merges, which is one of the practices behind a 99.99 percent crash-free and uptime record and a 98 percent first-time app-store approval rate across 100+ products shipped. Review reinforces our code quality and clean code principles, and it keeps knowledge shared across the team so a product is never dependent on one person. It also keeps the codebase clean enough to hand back to a client or maintain for years.
Where this applies
The PixelForce services where Code Review matters most - explore how we put it to work in client products.
Related terms
Other glossary definitions closely related to Code Review.
Frequently asked questions
Testing verifies that code behaves correctly by running it against expected outcomes, often automatically. Code review is a human evaluation of the code's design, readability, security and fit with the codebase - judgements that tests cannot make. The two are complementary: tests confirm the code works, while review confirms it is well-written and maintainable. Strong teams rely on both rather than treating either as sufficient alone.
Usually another developer on the team who is familiar with the codebase, and ideally not the person who wrote the change. For sensitive or complex changes, more experienced engineers or those who own the affected area may review. The goal is a knowledgeable second perspective. Many teams also rotate reviewers so knowledge spreads widely rather than concentrating in one person, which reduces risk across the project.
It depends on the size and complexity of the change, but reviews work best when they are prompt and the changes are small. A focused review of a modest change might take fifteen to thirty minutes, while a large or intricate change needs more care. Keeping pull requests small is the most effective way to keep reviews fast and thorough, because large changes are easily reviewed superficially.
The mechanical parts can be. Linters, formatters, static analysis and automated tests can check style, catch common mistakes and verify behaviour without human effort, and many teams run these in a pipeline before human review. However, judgements about design, readability and whether a change is the right approach still require a person. Automation handles the repetitive checks so human reviewers can focus on what matters most.
Focus on the code rather than the author, and explain the reasoning behind suggestions so they are educational rather than just corrective. Distinguish between issues that must change and minor preferences, and acknowledge good work as well as problems. Keep the tone collaborative, since review is a conversation aimed at the best outcome, not a test to pass. Prompt, specific and respectful feedback keeps the team moving and learning.
Have an idea worth building?
Whether you are validating a concept or scaling a product, our Adelaide team can scope it properly. Book a free consultation and we will map the fastest path from idea to launch.
- Top Clutch App Development Company · Australia
- 100% in-house · Adelaide HQ
- 100+ products shipped
- 99.99% crash-free