How Manual Code Review Affect Your Developers

In the fast-paced world of software development, maximizing productivity is key to ensuring that projects are delivered on time and meet high standards of quality. One crucial practice to maintain code quality is manual code review. During a manual code review, one developer checks another's code to ensure it meets coding standards, is free from bugs, and adheres to the project’s overall goals.

While this practice is vital, it has notable effects on the productivity of development teams. From time consumption to missed opportunities for innovation, manual code reviews can be both a blessing and a hindrance. In this post, we’ll dive into how manual code reviews can affect developers’ productivity and offer some suggestions for improving the process.

Challenges

The Time-Consuming Nature of Manual Code Reviews

Manual code reviews can significantly impact productivity because of the sheer time commitment involved. A developer submitting a pull request may spend hours carefully reviewing someone else’s code, evaluating its structure, performance, and correctness.

This process is necessary, but it comes at a cost. Developers could be spending that same time working on new features, solving bugs, or addressing performance issues, all of which directly contribute to project progress. Instead, they're pausing their development work to evaluate someone else's code.

Even worse, if the review process is delayed or not prioritized, it can create bottlenecks in the development cycle. What should be a quick feedback loop might stretch out unnecessarily, causing delays in merging code and leading to a lag in feature releases or bug fixes. In larger teams, this can mean that multiple developers are waiting for reviews before they can proceed with their own work, leading to a cascade of inefficiencies.

Cognitive Load and Developer Focus

The process of manual code review also takes a mental toll on developers, leading to cognitive fatigue. Reviewing code requires intense focus and concentration. Developers must be vigilant, looking for bugs, security vulnerabilities, performance problems, and adherence to best practices.

This takes a developer's mental energy away from the task they were originally working on, potentially harming their productivity. Studies have shown that context switching—moving between tasks—can disrupt focus and lower overall productivity. A developer reviewing code may find it harder to jump back into their own tasks after a lengthy review session, which can lead to longer ramp-up times and fewer effective hours spent on development.

Additionally, the repetitive nature of reviewing code can lead to burnout. The mental strain from constantly reviewing large amounts of code without adequate breaks can result in reduced focus, sloppy reviews, and even resentment towards the process. Over time, this can create a cycle of diminishing returns, where developers become less effective at reviewing code due to fatigue, further affecting productivity.

The Risk of Delays and Bottlenecks

As teams scale, the manual code review process can become a bottleneck. In a small team, one or two developers may be able to quickly review and merge code, but as the team grows, so does the demand for code reviews. Reviews can pile up, and instead of being a quick check, they turn into lengthy processes that slow down development.

For instance, if a developer submits a pull request but has to wait days for the review, this halts their progress. They may be unable to continue with their next task until the code is approved and merged. As a result, developers who are waiting for code reviews lose valuable development time, leading to a disruption in the overall flow of the project.

This bottleneck problem becomes even more pronounced in larger projects or teams working on different parts of a product simultaneously. The delays caused by manual code reviews can negatively affect project timelines, pushing deadlines back or forcing teams to make last-minute compromises in quality or features.

Inconsistent Feedback and Lack of Standardization

While manual code reviews aim to catch bugs and improve the code, they are not always consistent. A reviewer may overlook certain issues or have a different understanding of best practices, leading to feedback that can vary in quality. What one developer sees as an essential change may be ignored by another.

This lack of consistency can create confusion and additional work for developers, who may need to go back and forth with reviewers to clarify expectations or adjust to new guidelines. It also adds uncertainty to the process. Developers may feel frustrated when feedback is unclear or contradictory, making it harder to improve their work effectively.

When feedback loops are prolonged and inconsistent, developers may feel their time is wasted. This frustration can lead to disengagement from the review process, reducing productivity and quality.

How to Improve Code Reviews to Boost Productivity

While manual code reviews can certainly affect productivity, there are several ways to optimize this process and ensure that it adds value without causing unnecessary delays or distractions.

1. Set Clear Review Guidelines

One of the biggest productivity killers is unclear or inconsistent feedback. Establishing clear guidelines for code reviews can help ensure that developers know exactly what to focus on during reviews. For example, developers should know whether they need to focus on code style, security, scalability, or performance.

Having a checklist or a set of standards that all developers adhere to can make reviews more efficient and less ambiguous. This will help streamline feedback, reduce back-and-forth discussions, and make the review process quicker for everyone involved.

2. Automate Repetitive Tasks

Not all tasks during a code review need to be manual. Automated tools for linting, formatting, and static analysis can help catch common mistakes such as incorrect syntax, unused variables, or style violations before the code even reaches the reviewer. Tools like ESLint, Prettier, and SonarQube can help catch these issues, allowing manual reviews to focus on higher-level concerns, like functionality, performance, and security.

By automating these repetitive tasks, you free up developers to focus on more impactful aspects of code quality while reducing the time spent on trivial fixes.

3. Break Down Reviews into Smaller Pieces

Instead of waiting for large chunks of code to be reviewed, encourage developers to submit smaller, more frequent pull requests. Reviewing smaller pieces of code takes less time, reduces cognitive load, and allows feedback to be provided more quickly. This makes it easier to catch issues early and ensures that developers can continue their work without unnecessary delays.

4. Encourage Collaborative Reviews

Rather than relying on one reviewer, consider implementing a system where multiple developers review the same pull request. This not only spreads the workload but also leads to more comprehensive feedback, reducing the chance of missing critical issues. Pair programming can also be an effective strategy to address code quality in real-time, reducing the need for lengthy post-development reviews.

5. Set a Time Limit for Reviews

To prevent reviews from dragging on for too long, set a maximum time limit for each review. This can encourage reviewers to focus on the most critical aspects of the code, speeding up the process and helping developers stay productive. You can also prioritize reviews based on urgency, ensuring that the most important changes are handled first.

Learn more on how Matter AI helps team to solve code review challenges with AI: https://matterai.dev