Code reviews are a crucial step in delivering high-quality, secure, and efficient software. Yet, one question often leaves teams debating how to approach their review process: Should we use manual code reviews, automated tools, or a mix of both? Each comes with distinct advantages and shortcomings, making it essential to understand when and how to use each method effectively.
For a broad view of review methodologies, see our AI Code Review &Automated Code Review: The Complete Guide, or check out the latest trends and tools in Best AI Code Review Tools.
TL;DR
Manual reviews are ideal for evaluating readability, logic, and design, while automated reviews excel at catching repetitive or technical issues like syntax errors and vulnerabilities. Aikido Security provides a hybrid solution, combining automated efficiency with actionable insights to optimize code quality and streamline development workflows.
What Is Manual Code Review?
Manual code review involves human developers inspecting code to ensure it meets predefined standards for quality, clarity, and functionality. Teams usually handle these reviews collaboratively, often leveraging pull requests in Git-based systems like GitHub or GitLab. Manual reviews are especially valuable for nuanced areas such as architectural decisions, business logic, or highly sensitive code-contexts where automated tools may lack understanding.
For practical examples of the benefits and mistakes to avoid, read Common Code Review Mistakes (and How to Avoid Them).
For workflows prioritizing source code security, check out Aikido’s secure source code solutions for best practices to strengthen review processes.
Pros of Manual Code Review:
- Context Awareness: Humans can interpret code logic, intent, and architecture-critical aspects that automated tools often miss.
- Design and Readability Checks: A detailed manual review ensures the code is readable, well-documented, and aligned with the project’s design principles.
- Knowledge Sharing: Collaborative reviews foster learning, helping team members improve their skills and domain understanding.
Cons of Manual Code Review:
- Time-Intensive: Reviewing code line by line can slow down your workflow, especially as codebases scale.
- Prone to Human Error: Even knowledgeable reviewers can miss subtle bugs or edge cases, increasing the risk of overlooked issues.
- Lack of Scalability: Manual review processes can become bottlenecks for larger projects or fast-moving teams.
If your team handles infrastructure as code (IaC), supplementing manual review with Aikido’s IaC security platform helps ensure consistent and secure deployments.
What Is Automated Code Review?
Automated code reviews use tools and scripts to scan your code for errors, vulnerabilities, and adherence to coding standards. These reviews are typically integrated into CI/CD pipelines, providing immediate feedback after code is pushed.
If your team’s focused on streamlining dev workflows, we recommend exploring Continuous Code Quality in CI/CD Pipelines.
Pros of Automated Code Review:
- Speed and Efficiency: Automated tools can analyze thousands of lines of code in seconds, offering immediate feedback.
- Consistency: Unlike humans, tools don’t get tired or distracted, ensuring consistent checks every time.
- Scalability: Perfect for large or complex codebases where manual reviews would be impractical.
Cons of Automated Code Review:
- Context Blindness: Tools can detect technical flaws but often fail to understand code intent or architectural patterns.
- False Positives: Many tools flood developers with alerts, including low-priority issues or false positives.
- Setup Complexity: Some tools are challenging to integrate into workflows, especially with legacy systems.
For a deep dive into automated review strengths and limitations, see Using AI for Code Review: What It Can (and Can’t) Do Today.
Manual vs. Automated Code Review: Direct Comparison
According to Gartner, 45% of organizations are adopting AI-driven code review and automation to boost deployment speed and reliability. Furthermore, research from IEEE revealed that automated reviews outperform manual checks in detecting certain types of vulnerabilities and repetitive errors, while manual reviews excel at uncovering nuanced architectural and business logic issues.
A GitHub study found that projects leveraging a mix of automated and manual reviews often ship higher quality code and resolve security issues more rapidly. However, it's important to note that Stack Overflow's 2023 survey indicates that human judgement is still highly valued-developers believe peer review remains vital for learning and long-term maintainability. Finally, data from the Linux Foundation shows that striking a balance between manual and automated approaches leads to more successful open source projects.
When to Use Manual Reviews:
- Reviewing critical or high-impact code changes.
- Assessing architectural decisions, readability, or algorithm quality.
- During onboarding to teach tools, practices, or domain knowledge.
When to Use Automated Reviews:
- Catching syntax errors, performance issues, or known vulnerabilities.
- Continuously evaluating code during rapid development cycles.
- Scaling quality assurance without adding significant overhead.
Strike the Perfect Balance with Aikido Security
Why settle for choosing between manual or automated reviews when Aikido Security seamlessly integrates the strengths of both? Aikido Security provides a unified platform that combines AI-powered automation, deep contextual insights, and practical tooling-making it ideal for scaling engineering teams and tackling complex codebases.
For a comprehensive look at supporting tools, don't miss Best Code Review Tools, which includes practical comparisons and insights.
What Makes Aikido Stand Out?
- AI-Powered SAST & Automation: Aikido’s AI SAST and IaC Autofix automatically scans for vulnerabilities, insecure code patterns, and misconfigurations, offering clear, actionable fixes developers can trust.
- Advanced API Scanning: The API scanning feature ensures surface-level and deep vulnerabilities within your API endpoints are uncovered, protecting your interfaces from common exploits and emerging threats.
- Noise Reduction: With strategic noise reduction, Aikido cuts false positives by over 90%, so your team focuses only on genuine risks and saves time on triage.
- Comprehensive Compliance Support: Aikido automates compliance processes for frameworks like SOC 2, GDPR, and HIPAA, providing audit-ready posture management and detailed reporting with minimal manual effort.
- Seamless Git Integration & Real-Time Feedback: Integration with platforms like GitHub and GitLab means that Aikido embeds automated review, feedback, and remediation directly into your workflow, giving actionable insights at every stage of the CI/CD pipeline.
With these capabilities, Aikido Security enables your team to streamline code reviews, elevate security, and accelerate delivery-without compromising on quality.
Integrating Manual and Automated Reviews in Practice
Combining the human touch of manual reviews with the speed of automated tools provides the most comprehensive coverage. Here’s how you canbalance both:
Step-by-Step Guide:
- Use Automation First: Begin with an automated scan to handle repetitive or technical checks like syntax, security vulnerabilities, and adherence to style guides.
- Follow Up with Manual Reviews: Assign team members to focus on high-priority areas like logic, architecture, and business-critical sections.
- Continuous Feedback Loop: Automate feedback on recurring issues through CI/CD pipeline scans, but use manual reviews to track progress over time.
See real-world examples of this approach in Continuous Code Quality in CI/CD Pipelines.
Example Workflow with Aikido:
- Stage 1 (Pre-commit): Aikido runs automated scans for technical issues when developers submit code.
- Stage 2 (Pull Requests): Team leads perform manual reviews, addressing design logic and application-specific nuances.
- Stage 3 (Post-merge): Aikido continues monitoring code for vulnerabilities, ensuring ongoing code quality.
Conclusion
There is no universal "best" between manual and automated code reviews-they each bring unique advantages to the table. Manual reviews excel in context-specific evaluations like logic and design, while automated tools dominate repetitive, technical analyses. The ideal approach combines both methods to maintain efficiency, minimize errors, and boost code reliability. Aikido Security makes this hybrid approach effortless by blending AI-driven automation with actionable insights, ensuring your team is equipped to scale securely and efficiently.
Discover more strategies with Using AI for Code Review: What It Can (and Can’t) Do Today or take a look at how review culture shapes Code Quality: What Is It and Why It Matters.
Try Aikido Security today to experience the future of code review. Signup here and streamline your development process.
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