Best practices for better code reviews

Code reviews might be so routine at your organization that you don’t question the how or why behind them. However, as Google software engineers points out, reviewing code is an art that requires finesse and creativity. If you feel like you’re treating code reviews as a mundane checkpoint in your day, this post will challenge you to think differently.

With thoughtful code review, you can not only debug and ensure code quality but also foster teamwork, security, and overall productivity. Here are some best practices to make code reviews more efficient and effective.

Benefits of code reviews

Great code translates into high-quality software. Code reviews are the gatekeepers between development and end product, helping to catch bugs early, enforce coding standards, and generate readable and maintainable code.

Identifying defects early in the development cycle can also cut costs. A bug that might cost $100 to fix in the planning stages could easily spiral into a $10,000 disaster in production due to the domino effect a bug can have on the software development lifecycle.

Code reviews also encourage knowledge sharing. As team members review each other’s work, they pick up new skills and better understand the codebase. This collaborative environment enhances the team's expertise and overall business continuity in case of employee turnover.

Types of code reviews

There is no “one size fits all” when it comes to code reviews, with different scenarios requiring specific types of reviews. Teams may use a combination of the techniques below, depending on the project.

• Formal code reviews: In ****these ****structured meetings, developers present their code changes for detailed inspection. Because they are more time-consuming, formal code reviews work best for high-impact or complex code requiring extensive scrutiny.
• Tool-assisted reviews: Developers can conduct asynchronous reviews using platforms like GitHub, GitLab, or Bitbucket. These tools support inline commenting, version control, and automated checks for syntax and style compliance, with clear records of revisions and feedback.
• Pair programming: With this technique, two developers work in tandem to write and review code. It’s like a buddy system for the tech world, encouraging continuous feedback and prompt error detection.

Best practices for code reviews

If you think of code review as both an art and a science, then you’ll set your team up for success. The goal is to foster a culture where developers view code reviews as a positive addition to their routines, not a dreaded activity. Follow these best practices to get everyone aligned.

1. Keep reviews small and manageable

Reviewing more than 400 lines of code at once is overwhelming and may lead to missed issues. In fact, developers tend to be at their sharpest within the first 200 lines of code, after that, their ability to catch defects typically drops.

2. Focus on readability and maintainability

Good code is easy to read and maintain, making future modifications easier. Reviewers should check that variable names are meaningful, functions are concise, and comments are used wisely to explain complex logic.

3. Be constructive and supportive

Aim for respectful, objective feedback that improves the code and encourages learning without criticizing the developer. For instance, asking, “Would using X improve performance here?” is more tactful and constructive than bluntly stating, “This is wrong.”

4. Check for adherence to coding standards

Ensure the code follows the team’s style guides, formatting rules, and company best practices. Checking for proper indentation, naming conventions, and file organization should be standard practice.

5. Encourage automated testing and CI/CD practices

Implement continuous integration and continuous deployment (CI/CD) to enable teams to merge changes frequently and automatically run tests. If all tests pass, the code is deployed to production. This approach helps teams catch problems early and release new features and fixes quickly and safely.

6. Leverage code review tools

Use tools like SonarQube and Code Climate to automate repetitive checks, including style compliance, syntax validation, and security scans. This approach lets reviewers focus on more complex issues like logic errors and architectural decisions.

7. Look beyond functionality

While functionality is essential, reviewers should also consider performance, security, and scalability. For instance, checking for efficient algorithms and secure authentication practices enhances the overall quality of the code.

Common pitfalls to avoid

Following the best practices above will help you instantly upgrade your code reviews. Equally important? Avoiding the missteps that can throw your reviews off track:

• Overly nitpicky or unhelpful comments: Don’t cling to minor stylistic issues or personal preferences. Instead, prioritize feedback that has a real impact, including functionality, maintainability, and security.
• Rushed reviews: Give reviews the time and attention to detail they need. Rushing through them is a recipe for missed defects and inconsistent feedback.
• Ignoring documentation and test coverage: For maintainability and reliability, ensure all new code is well-documented and thoroughly tested.
• Making it personal: Focus on the code, not the developer. Critiquing the code rather than the person keeps the process respectful and productive.

Code review metrics

What metrics are important to track? Prioritize the following for effective code reviews:

• Defect density: Measures the number of defects per 1,000 lines of code. Lower defect density indicates higher code quality.
• Review coverage: Percentage of code changes that have been reviewed. Higher coverage ensures consistent quality control.
• Time to review completion: Evaluates how long it takes to complete a review. Faster completion times improve productivity but shouldn’t come at the expense of quality.
• Rework rate: Frequency of changes required after the initial review. Lower rates indicate effective feedback and high code quality.

These metrics provide insights into the team’s review process and help identify areas for improvement.

Security vetting in code reviews

Security should always be a priority during code reviews. Reviewers must look for risks like SQL injections, hardcoded passwords, and weak authentication. Finding these issues early can prevent security breaches and other headaches down the line.

Static application security testing (SAST) can help identify areas vulnerable to attack, while dynamic application security testing (DAST) simulates a hacker’s perspective to find external threats. Reviewers should also prioritize security during code reviews, following best practices for authentication and encryption to keep the application safe from attacks.

Building a strong code review culture

With the right code review process, you can assemble a team that’s eager to collaborate and committed to continuous learning. To build this culture:

• Encourage peer learning through reviews: Pair senior and junior developers to foster mentorship and knowledge sharing during code reviews.
• Set clear expectations: Establish guidelines for review quality and timelines to maintain a consistent feedback cadence.
• Create a safe space: Promote trust and collaboration via constructive criticism and clear guidelines for delivering code reviews that help everyone grow.

Better reviews, better code

Code reviews are the foundation of quality, security, and maintainability. By adopting the best practices above, teams can boost productivity and establish a culture that welcomes feedback and professional growth.

As technology evolves, a strong code review culture will remain essential for delivering high-quality software solutions. You can lead the way by incorporating these strategies into your development workflow, starting today.