How to do a Code Review?

1. März 2022 – Lesezeit: 6-8 Minuten

Code Reviews are an important element of the software development process that should be done on a regular basis.


While automated tests, peer reviews, and quality assurance can detect errors, typos, architectural faults, and other problems, in many circumstances, only a fresh pair of eyes can determine whether the code's design, logic, and quality are up to par.

The Code Review is, in most situations, a “Make It or Break It” situation. The Code Review is frequently overlooked and undervalued, and it is occasionally ignored for misleading reasons.

A Good Code Review necessitates a delicate balance of meticulously specified procedures and a welcoming, collaborative atmosphere. Overly Strict Code Reviews can stifle production, while random approaches are typically ineffective. Managers must find a happy balance between quick and productive peer review and fostering open communication and information sharing among colleagues.

Why to do a Code Review?

Regular code reviews, while they may not appear to do so at first, are capable of streamlining and expediting software development like no other. The following advantages were already revealed in the Best Secrets of Code Review:

  • Code Quality has improved.
  • There are less errors in the code.
  • Cycle times for development and testing are shorter.
  • User satisfaction has improved.
  • Impact on technical support is minimized.

However, there are a few more code review advantages that can be added to the list since then. In fact, having a coworker evaluate your code is regarded to be the most effective approach to detect and fix bugs these days.

Code Reviews, when done correctly, speed up development, reduce the amount of labor required by Quality Assurance teams, and save money in the long term. Regular Code Reviews also contribute to a sense of “ownership” for any piece of code that developers write, and they serve as an excellent learning opportunity for more junior members of the team.

How to do a Code Review?

Given these advantages, it's no surprise that many product owners regard code reviews as an important component of the software development process. The truth is that code reviews may benefit any team, regardless of the technology or development technique used. Let's look at how to do a Code Review.

Reviewing for more than 60 minutes at a time is not recommended

You should not evaluate code too quickly or for too long in one sitting, just as you should not review code too quickly. When people engage in any activity that requires sustained effort, their performance begins to deteriorate after around 60 minutes. Breaking away from a task for a period of time has been shown in studies to boost work quality. Conducting more frequent assessments should eliminate the need for a lengthy review in the future.

Before the Review, Authors should comment Source Code

Authors should annotate code before submitting it for review because annotations help the reviewer through the changes, indicating which files to look at first and justifying each code change. To make the process easier and add more context, annotations should be directed at other reviewers. As a bonus, the author will frequently discover additional problems before the peer review process begins. Because fewer defects exist generally, more bugs detected prior to peer review will result in lower defect density.

Make use of Checklists

It's extremely possible that each member of your team makes the same ten errors again after time. Deficiencies are the most difficult defects to find because it's difficult to evaluate something that isn't there.

Checklists are the most effective method for avoiding frequent errors and overcoming omission detection challenges. Code review checklists also establish clear expectations for team members for each type of review, and they may be kept track of for reporting and process improvement.

Create a procedure for resolving any issues that are detected

Even after time-boxing reviews, limiting the number of lines of code examined per hour, and setting essential metrics for your team, the Code Review process is still missing one step. What will be done about the bugs? Many teams don't have a systematic procedure for correcting the defects they've worked so hard to identify, despite the fact that it seems obvious.

The best way to ensure that defects are fixed is to use a collaborative code review platform that allows reviewers to log mistakes, argue them with the author, and approve code updates. Because issues detected during review occur before code is handed to QA, they are unlikely to be recorded in the team's traditional defect tracking system without the use of an automated tool.

Give Helpful Feedback

Instead of being critical, try to be constructive in your feedback. Instead of making pronouncements, you can achieve this by asking questions. Also, remember to give appreciation in addition to constructive criticism.

Giving comments (or even performing your evaluation) in person will help you convey in the appropriate tone.

At a time, No more than 400 lines should be checked

You're less likely to detect bugs if you try to evaluate too many lines of code at once. Each code review session should be limited to 400 lines or less. Setting a Line-of-Code (LOC) limit is just as critical as setting a time limit for the same reasons. It ensures that while you're examining the code, you're at your best.

Examination rates of fewer than 500 LOC per hour should be avoided

It's natural to rush through a review in the hopes that someone else will see the errors you overlook. Fault density lowers dramatically at rates faster than 500 LOC per hour, according to studies. The most successful code review is one that is completed in a fair amount of time and at a slower pace.


Because Code Review is a quick way to check the efficiency and quality of existing source code, as well as assess its growth potential, you might want to consider it if your app users complain about bugs or poor performance, or if you simply want to know if the app is being developed according to the highest standards and best practices.