Before we begin, let’s know what precisely a code review is. Peer Code Review, or simply Code Review, is an act of consciously and systematically calling together with fellow programmers to check each other’s code for errors and other issues. It is done mainly by viewing and reading parts of its Source Code. 

Code Review is done with the motive to find bugs and resolve the errors and issues, enhancing the quality of the product. 

How can an effective code review be performed? 

There are a few things to keep in mind before we proceed further. 

1. Code reviews should happen after automated checks have been completed successfully but before merging the code to the repository’s mainline sector.
2. The author’s responsibility is to submit only the complete, self-reviewed codes to save time. 
3. Before proceeding to Code Review, set goals. The goals include acceptable standards in the company. Having set standards makes sure that each software developed meets the company’s standards. Communicate about the standards within the team members to work accordingly. 

Coming back to how exactly can an effective code review be performed?  
Well, various practices might be helpful. 

1. Define a Code Review Process. 

Having a defined code review process helps everyone to be on track. 

2. Use a code review checklist. 

Use a checklist to make sure nothing is missed out.  

3. Use of annotations by authors 

Annotations help the reviewers understand the code in a much better and easier way. Furthermore, what each block of code does. But remember not to overdo it. 

4. Define a process to fix the defects 

After reviewing the codes, a defined approach towards resolving the errors will assure it is done most effectively. 

5. Built an environment for motivation and learning 

Promote a positive code review culture when it’s essential to learn and grow together. 

Why is code review critical? 

1. Code review helps developers learn the code base and help them learn new technologies and techniques that grow their skill sets.
2. Code review also proves to help keep the codes consistent. Many team members are building different features parallelly, so consistency is essential.
3. Errors such as dead code, logic, or algorithm bugs are often much easier to spot by the critical reviewers with an outside perspective than the author whose brainchild it is.
4. It helps to identify if the code is as per the company’s standards. When further improves the quality of products or projects as a whole. 
5. Identify the bugs or issues that might affect the performance or standard of the product and resolve them together.
6. It also ensures that inevitable mistakes are not repeated by developers or authors again, which can be helpful. 

So now you know about what a code review is, how it’s done and why it’s essential. In the beginning, code reviewing might seem time-consuming, but when done right, it saves time in the long run. Keep in mind code reviews are classless. So it is not just a senior team member reviewing a junior team member’s code or being the senior-most person on the team that does not imply that your code does not need review. Code review should happen across the team in every direction. Knowledge knows no bounds!