Kakao FE Kay Presents 5 Principles for Effective Code Reviews

Kakao Talk FE Part's Kay presented the reviewer's attitude for effective code reviews and five principles, based on their experience with code reviews during technical onboarding education for new graduate hires. Reviews are essential not just for detecting errors, but also for reducing technical debt and sharing knowledge, and the reviewer's attitude determines their effectiveness.

5 Core Principles

1. Explain the reason for improvement specifically: Subjective or abstract feedback causes confusion, so clear grounds for necessary changes must be provided.
2. Suggest direction instead of answers: Rather than directly fixing the code, provide keywords or search methods to encourage the reviewee to think and learn on their own.
3. Emphasize consistency: Provide feedback to ensure adherence to project convention rules, and maintain consistency in repetitive patterns within the code.
4. Approach it as a learning process: First understand the reviewee's intent and ask questions, making them feel it is an opportunity for growth rather than a homework check or surveillance.
5. Avoid reviews for the sake of reviews: If there is no feedback to give, do not force criticisms; leaving praise for well-written code is also good communication.

Practical Tips and Precautions

During reviews, it is important to grasp the context of the entire code rather than small commit units, and using Pull Request templates can reduce mistakes for both reviewees and reviewers while clearly conveying work content. Additionally, in areas where readability is subjective, such as choosing between if/else and ternary operators, sufficient discussion should take place rather than criticizing the developer's tendencies. Code reviews involve high communication costs, but good reviews are a worthwhile investment despite taking longer, as they contain the benefits and rationale for changes.