Code reviews are a fundamental part of software development. Done right, they’re not just about spotting bugs – they’re about improving code quality, reducing technical debt, and fostering a collaborative learning environment. Whether you’re a developer, tech lead, or engineering manager, a thoughtful review can be a game-changer. In this guide, we'll break down the essentials of a great code review – from what to look for to why it matters.
Why Code Reviews Matter
Code reviews might seem like a quality check before deployment, but they do so much more. When handled well, they:
- Build shared understanding: Ensuring your team is aligned on the code, approach, and reasoning.
- Onboard new team members: Reviews are a great way to bring newcomers up to speed on your codebase.
- Reduce long-term maintenance costs: Clear, readable code is easier to update and scale.
- Spot potential edge cases: Reviews help catch issues you might have missed during development.
- Help developers grow: Providing and receiving feedback is one of the fastest ways to improve as a developer.
A good code review is about clarity, collaboration, and getting it right together – not just finding mistakes.
Key Areas to Focus on in a Code Review
What makes for a high-quality code review? Let’s break it down:
1. Clarity and Intent
Can someone else easily understand what the code is doing and why?
Readable code is maintainable code. Look for clear variable names, logical structure, and simplicity. If a block of code requires long comments to explain its purpose, it’s usually a sign that the code could be clearer on its own. Comments are helpful for explaining “why” something is done, but the code itself should always answer “what” and “how.”
2. Correctness and Edge Cases
Does the code do what it’s meant to? What happens when things go wrong?
It’s essential to think beyond the happy path. What if an API returns null or an input is malformed? Does the code handle unexpected scenarios? Reviews should consider edge cases, error handling, and resilience – not just whether the code works as expected under ideal conditions.
3. Security, Performance, and Accessibility
Even when teams move quickly, we can’t afford to overlook the basics.
- Security: Are inputs being validated? Is sensitive data handled correctly?
- Performance: Are we being efficient with resources, especially when dealing with large datasets or complex queries?
- Accessibility: Is the code accessible? For front-end code, is it using semantic HTML and considering things like screen readers and keyboard navigation?
Even if you’re not an expert in these areas, asking questions like “Is this the most efficient approach for handling large data?” can trigger important conversations.
4. Consistency with the Codebase
Does this code align with the existing project’s patterns and architecture?
Consistency isn’t just about style; it’s about ensuring your code fits within the larger framework of the project. Sudden shifts in architecture or naming conventions can cause confusion. Reviews are an opportunity to nudge the code back into alignment with the established structure and guidelines.
5. Test Coverage and Confidence
Are there adequate tests in place, and do they cover the critical areas?
Tests should validate both the expected behaviour and edge cases, providing confidence that new changes won’t break existing functionality. If testing is difficult or missing, it might indicate that the code could benefit from being split into smaller, more manageable pieces.
The Human Side of Code Reviews
Code reviews are more than just a technical exercise; they’re an important part of building a healthy team culture. The way we give and receive feedback plays a huge role in shaping that culture.
Instead of making demands, it’s important to ask questions that encourage collaboration. For example, asking, “Could this be refactored for clarity?” opens up a dialogue for improvement, whereas saying, “This code is too complex,” can feel more like a critique and shut down the conversation. This approach fosters a sense of teamwork and mutual growth.
It’s also essential to be generous with praise. Recognising a teammate’s clever solutions or the well-executed parts of their code not only boosts morale but also motivates the team to keep improving. Positive feedback highlights the strengths in the work and encourages the team to continue producing high-quality results.
Lastly, accepting feedback graciously is key to personal and professional growth. Remember, a code review is not about personal criticism—it’s about enhancing the work and learning from each other. Embrace feedback as an opportunity to improve and refine your skills, rather than taking it personally.
Avoiding Common Code Review Pitfalls
When conducting a code review, it’s easy to fall into certain traps that can hinder the effectiveness of the process. By being mindful of these common pitfalls, you can ensure that code reviews remain a valuable tool for improving code quality and fostering team collaboration.
One of the most frequent issues is reviewing too much code at once. Large pull requests can be overwhelming and difficult to review thoroughly. When a pull request contains too many changes, it becomes harder to focus on the quality and intent of the code. To avoid this, encourage smaller, more manageable changes. Breaking down large tasks into smaller, more focused pieces makes the review process more effective and less likely to overlook critical issues. This approach also makes it easier to identify patterns or problems in the code, as each review is focused on a specific area.
Another common pitfall is focusing too much on style rather than substance. While adhering to style guidelines is important for consistency and readability, the primary focus of a code review should be on the logic and behaviour of the code. Don’t get bogged down in minor details such as variable names or formatting unless they’re significantly impacting the readability or functionality of the code. Instead, dive deeper into the intent behind the code, whether the logic is correct, and if it performs as expected. A great code review goes beyond surface-level aesthetics and looks for potential issues in functionality, performance, and edge cases.
Lastly, it can be tempting to skip code reviews, especially when deadlines are tight or the pressure to deliver is high. However, this is often when a fresh set of eyes is most valuable. Skipping reviews may lead to missed bugs or overlooked design flaws that could affect the quality of the final product. A rushed code review can also result in a lack of collaboration and learning opportunities within the team. Even under tight timelines, making time for a proper review process ensures that the final product is reliable, secure, and well-constructed. A well-executed review may actually save time in the long run by preventing issues from arising in later stages of development.
By recognising and addressing these pitfalls, your team can make code reviews a more meaningful and productive part of the development process, ultimately leading to better-quality code and more effective collaboration.
Building a Healthy Code Review Culture
To make code reviews a true asset, they need to be seamlessly integrated into the development process, rather than seen as a final step before deployment. It’s important that code reviews become a natural part of your team's workflow, not something that’s rushed or left to the last minute before a release. Allocating dedicated time for reviews helps maintain quality and consistency across your projects.
It's also essential to celebrate thoughtful feedback. Code reviews should be viewed as a valuable opportunity for learning and growth, rather than a chance to criticise. This mindset fosters a collaborative culture where everyone, regardless of their experience level, feels empowered to contribute and improve.
Creating shared guidelines is another key aspect of building a healthy code review culture. Having a clear understanding of what constitutes “good” code within your team ensures that reviews align with the team’s overall expectations and objectives. This consistency helps maintain high standards across the codebase.
Finally, code reviews should not be restricted to senior developers. Junior developers should be encouraged to review code from senior team members as well. This practice brings fresh perspectives to the table, often uncovering issues or insights that might be overlooked by those more familiar with the code.
Final Thoughts
At MadeCurious, we believe in the power of collaboration and curiosity in every aspect of our work – and code reviews are no exception. They’re an opportunity to improve, learn, and grow together. A code review isn’t just about finding mistakes; it’s about ensuring that the work we do is clear, correct, and built for the long-term.
If you’re looking to improve your code review process or build a stronger development culture, let’s chat. We’re always up for a curious conversation.
