7 steps to create an effective code review guideline

What is a code review guideline?

A code review guideline is a set of rules for submitting and reviewing code changes in a project. It outlines the steps for creating a pull request, submitting it for review, and merging it into the codebase.

It's important because it establishes a clear and consistent process for collaborating. It can improve code quality, reduce review time, and ensure a smoother development process. Teams, developers, and managers can all benefit from a defined guideline.

What should you implement in your code review guideline?

1. Establish clear goals and objectives for the code review process.

Clear goals and objectives for the code review process are important to ensure that the review process aligns with the project's goals and focuses on the most important aspects of the code. To implement this guideline, stakeholders should:

1. Define the goals and objectives of the code review process.

2. Communicate them to team members.

3. Regularly review and evaluate them to ensure relevance.

Once you have done the preparation work, you will have your first guideline in place. I'm adding an example to help you start:

Goals:

- To ensure that the code meets the project's functional and non-functional requirements
- To identify and correct defects in the code
- To improve the overall quality of the codebase
- To provide a mechanism for sharing knowledge and best practices among team members

Objectives:

- To review all code changes before they are merged into the main codebase
- To provide constructive feedback to developers to improve the quality of the code
- To ensure that the code is consistent with the coding standards and guidelines
- To ensure that the code is well-documented and easy to understand
- To identify and correct defects in the code
- To ensure that the code is scalable, maintainable, and extensible
- To identify and share best practices and knowledge among team members

2. Clearly define the roles and responsibilities of each team member involved in the review process.

Clear roles and responsibilities for each team member involved in the review process are important to ensure efficiency and prevent confusion.

You don't want people that have nothing to do with a specific pull request reviewing it. This will only slow down the process, waste time and create frustration.

Roles and Responsibilities:

- Author: The developer who submits the code for review
- Reviewer: The team member who reviews the code and provides feedback. How should we assign the reviewer?
- Lead Reviewer: The team member responsible for coordinating and overseeing the code review process
- Approver: The team member who approves or rejects the code changes after the review process

3. Set guidelines for the scope and focus of the code review, including the size of pull requests and the areas of code to be reviewed.

Here are some steps to define the scope and focus of the code review:

1. Define the scope and focus of the code review.

2. Set guidelines for the size of pull requests.

3. Establish criteria for evaluating code.

4. Communicate the guidelines clearly to team members.

Guidelines for the Scope and Focus of Code Review:

- Define the scope of code review: Which files and areas of the code should be reviewed?
- Define the focus of code review: Which aspects of the code should be prioritized for review (e.g., functionality, performance, security)?
- Set guidelines for the size of pull requests: What is the maximum size of a pull request that can be reviewed effectively?
- Establish criteria for evaluating code: What criteria should be used to determine whether the code meets the project's standards and requirements?
- Communicate the guidelines clearly to team members: How should team members be informed of the guidelines, and how should they be enforced?

4. Define standards for code formatting, commenting, and documentation.

Defining standards for code formatting and code review, in general, is hard. I tried to summarize the main steps to it easily:

1. Identify the coding standards to follow.

2. Define guidelines for commenting.

3. Set documentation requirements.

4. Determine the tools to be used.

5. Communicate the guidelines.

Standards for Code Formatting, Commenting, and Documentation:

- Identify the coding standards to follow: Which coding standards should be used, such as indentation, line spacing, and naming conventions? How many lines max per pull request (you should not [review more than 400 lines to reduce pickup time](https://axolo.co/blog/p/how-to-reduce-cycle-time))
- Define guidelines for commenting: What types of comments should be used, and where should they be placed in the code? How should comments be formatted?
- Set documentation requirements: What types of documentation are required, such as high-level design documents, API documentation, or user manuals? What is the expected level of detail?
- Determine the tools to be used: What tools will be used to ensure that code formatting, commenting, and documentation standards are enforced?
- Communicate the guidelines: How should team members be informed of the guidelines, and how should they be enforced?

5. Determine the frequency and timing of code reviews, and ensure they are integrated into the development process.

The two most important things for this part are the frequency and timing of code reviews. I have written an article specifically on how to review code, so I will just summarize the main steps below.

Don't forget that code reviews should be fast, daily, and well-tested. So for this part, you should:

Frequency and Timing of Code Reviews:

- Define the frequency of code reviews: How often should code reviews be conducted (e.g., daily, weekly, or monthly)? How long should they last?
- Determine the timing of code reviews: At what point in the development process should code reviews be conducted (e.g., before merging, after merging, or during testing)?
- Ensure integration into the development process: How should code reviews be integrated into the development process, and how should they be prioritized alongside other tasks?

1. Define the frequency of code reviews

2. Determine the timing of code reviews

If you want to make sure your code reviews are quick and efficient, I recommend you to read this article: How to reduce your cycle time and code review time?

6. Encourage a positive and constructive culture around code reviews, emphasizing the importance of collaboration and learning.

1. Emphasize the importance of learning.

Encourage team members to view code reviews as an opportunity for learning and improvement, rather than a critique of their work.

2. Foster a collaborative environment.

Encourage team members to work together to identify issues and propose solutions. You should especially focus on that if your team is mostly working remotely.

3. Recognize achievements and contributions.

Acknowledge team members who have made significant contributions to the review process, and recognize those who have demonstrated a positive and constructive attitude towards feedback. This is your time to motivate the team and shine as a manager!

4. Regularly review and refine the culture around code reviews.

This will help ensure that the culture remains positive, constructive, and aligned with the goals of the project. Be sure that your team knows that it is heard. If you're interested in building the best work environment for your developer, you should also check out our advice for a developer experience survey template.

That's it! Now I hope you know how to create your code review guideline, if you're interested in a markdown template, I have summarized everything in an open-source readme file.