code review services
Mariusz Interewicz Updated: 10 Jan 2023 8 min to read

Code Review Services – Why is it Always Worth Verifying Code Quality?

Whenever an author completes writing a book, it is not published immediately because it might contain some mistakes. Therefore, it is carefully reviewed by the editors, who read it, suggest some changes, and make sure that it is good to go for publication.

The same is the case with written code. Other developers should review a piece of code written by a developer to find any potential problems in the source code to ensure that the perfect code is shipped to the customer.


Code reviews can be performed by other fellow developers within the organization, or code review services can be obtained. These code review services provided by some firms provide access to developers who are experts in source code review to get rid of bugs, create conformity to standard practices, and enhance security.

What is Code Review?

Code review (also called peer code review) is an activity in the software development lifecycle which can ensure high-quality code. It is primarily done by systematically examining the source code written by a developer to find potential bugs and noncompliance with standard practices to increase code quality.

Code Reviews not only help detect and handle mistakes but also act as a knowledge-sharing activity among developers on the team, and it can increase collaboration on a project.

Code reviews ought to be integrated into a team’s current workflow. For instance, if a team is utilizing task branching workflows, start a code review after all the code has been produced, the automated tests have been run, and they have passed, but before the code has been merged. By doing this, the primary development stream is shielded from bad coding mistakes, and the code reviewer’s time is devoted to looking for things that machines miss.

Employing programmers to evaluate code outside the group of developers who authored it originally is a typical practice. It ensures the development team’s objectivity and a superior end product. Code review services greatly accelerate the creation of software products.

In the past, the code review processes did not use to be systematic and structured, unlike code reviews in the present. In the past, a code review involved several people who sat together and studied printouts of the code to find potential mistakes. The concept of a rigorous, systematic code review swiftly gained popularity starting in 1976 when IBM’s Michael Fagan released his innovative publication, “Design and Code Inspections to Reduce Errors in Program Development.”

Code reviews have still undergone a significant evolution, and there are now a variety of variations to pick from, just like everything else in the world of computing and software development. Long formal code review processes are no longer generally essential, except in software engineering scenarios where there is virtually no room for error, such as in mission-critical systems where human safety becomes a topmost priority.

Based on our experience, Code Review is not only a quality check, but also a great opportunity for extra improvements to existing software. Better performance, higher security, faster functionalities, and better-optimized code are all benefits that spread throughout the company. This not only allows you to deliver better services to users but also to cut costs and better achieve business goals. Paul Jackowski CEO, ASPER BROTHERS Contact Me


The importance of Code Review in Software Development

In a book called Code Complete by Steve McConnel, it is said that code inspections are 60 percent effective, which is significantly higher than software testing techniques. A real-world example of the effectiveness of peer review is Aetna, which is an insurance company that utilized code reviews and successfully rooted out 82% of errors in their system, resulting in a 20 percent reduction in development costs. This highlights the immense importance of code review. Some of the specific benefits that can be achieved using code reviews are:


Different programmers have different coding styles, and when several developers are working on a project, there will be variations in the style and formatting of code. Most formal organizations ideally want all their code to reflect a consistent style and to exhibit best coding practices. When code is being reviewed, it gets easier to pinpoint issues of bad coding practices. The code might work perfectly but still could have bad coding practices followed, which should be addressed. This helps achieve consistency for all the code written by different developers within an organization. It becomes increasingly important when code is public, such as open source code. Making the code consistent and standard and ensuring conformance to good coding practices also means that the end product will be of higher quality.

Code Quality and Performance

The development team can ensure higher quality by doing a code quality review during the process. Even though getting the proper results, some parts of the code might reflect poor code quality due to deviation from standard practices, such problems can ultimately lead to poor performance issues. Handling the quality concerns during this stage helps in ensuring a better quality product that has optimal performance.

Cost Reduction

According to Celerity, the cost of fixing a bug in the production phase is exponentially higher than that of fixing a bug in earlier stages of the software development lifecycle. A strong example of this claim is NASA’s Mariner 1 spacecraft, which had to be destroyed soon after its takeoff due to a mistake in the code. According to one of the official statements, the data editing program’s coded computer instructions left off a hyphen, which caused the spaceship to receive the wrong guiding signals. The overall loss due to this simple bug was 18 million dollars.

If the mistake had been addressed earlier, the loss would have been exponentially lower than actually faced. Furthermore, a problem in the Note 7 smartphone model Samsung caused the phone to catch fire, ultimately causing the company a huge loss. It was estimated to have cost the company 17 billion dollars. This shows that the cost of a bug if discovered in early phases, is exponentially lower than the cost associated with it if it is found in production. Code reviews help detect bugs and problems in the early stages, thus reducing potential costs.

Knowledge Sharing and Maintainability

If a single developer is working on an important module of the program, it means that there is a single point of failure. That developer might go on vacation or fall sick, it can seriously impact the progress of the project if no one else has sufficient familiarity with the program. Using code reviews, multiple developers understand the code and thus provide the development team with a potential substitute in case of problems. In this way, code review becomes similar to pair programming, where one programmer writes the code, and another one provides input for improvements. The code becomes more maintainable because the original author writes comments to help the reviewer understand the code properly, which in turn acts as documentation for maintaining the code later on. Furthermore, it can be a learning activity as well, where the code written by an experienced developer is understood by a junior developer in the development teams of an organization.

QA testing becomes Easier

If there is no code review done, then an entire load of finding bugs falls upon the Quality Assurance team, which makes this process difficult and less effective. Some bugs can only be detected by careful code study during code review, while others can be found during the quality assurance stage. If the code review is skipped, it means that some of the bugs will go undetected during the testing phase.


Code Review Process in Steps

code review process

The specific steps in code review depend on the form of cooperation and the techniques established. However, communication between the participants in the process is always crucial.

The code review process may vary slightly from organization to organization. Still, these are the steps that are essential for performing a successful code review, whether it is being performed in-house or third-party developers are being hired to avail their code review services. The code review process has the following steps:

Kick-off Session

A kick-off meeting is held to understand the requirements of the code review. If a firm is providing code review services, then stakeholders from both sides are present in the kick-off meeting to provide their input for a better understanding of design and architecture, coding practices, business logic, etc. During this session, the key outcomes of the code review are gathered and documented, which serve as a benchmark for measuring progress in later stages of the code review. These outcomes could be related to code quality, maintainability, security or scalability, etc.

Estimation of Timelines and Milestones

An initial analysis of the source code is performed to understand the potential problems and vulnerabilities present in the code. The analysis is performed in the form of a complete or partial review to get a better idea of how much effort must be put into the code and to estimate the aspects of coding which need improvement. This analysis helps in estimating milestones that the code review process will accomplish and also the timelines associated with these milestones. If a third-party firm provides code review services, then these estimations are provided to the client for approval.

Source Code Review

After the milestones of the code review process are understood, the next step is to do a manual source code review, in which the code is analyzed the code line-by-line to detect any bugs, security vulnerabilities, or noncompliance with best coding practices, style guidelines, and performance problems, etc. The manual review also takes the design and architectural concerns into consideration.

Detailed Report

The problems detected during the source code review are recorded and documented systematically in a formal report. The report contains a thorough explanation of the problems and the potential issues that might arise due to these bugs. Furthermore, the report also details suggested solutions to these problems.


Code Review Checklist

The code review process considers several factors. It is best to ensure that all concerns are addressed at the end of a code review. Some of the important items that must be checked off during the code review are discussed below:

  • Design and Architecture

The information about design and architecture is gathered during the kick-off meeting. The design and architecture patterns should be considered when performing the code review. All the code should follow the design and architecture requirements.

  • Code Quality

In general, the review process should produce high-quality code thus, reviewing the code for quality is a prime concern and must be given priority. The review should record quality issues, their impact, and possible solutions.

  • Maintainability

Some pieces of code are very difficult to maintain in the future due to the high dependability of old versions. During the code review, these issues should be pointed out, and high maintainability should be ensured.

  • Scalability

It must always be assumed that the system will eventually scale up, and thus the code should be written to fulfill the scalability requirement, making the system easier to scale. During the review, the analysis should be performed to understand whether some parts of the code will hinder scaling the system at later stages and suggest possible changes to ensure scalability.

  • Security

The presence of security flaws in a system can make it vulnerable. Sometimes the security concerns are not considered when writing the code, and it might become increasingly difficult to make the code secure during later stages of the software development lifecycle. Therefore, it is important to analyze the code for security concerns during the code review stage.

  • Tests Review

If the code review is being performed on a system that has codes for automatic testing as well, then these tests should also be analyzed. The overall quality of the testing should be analyzed along with an examination of unit tests and code coverage. The test code should be made clean and readable, and any problems in this code should also be addressed.

  • UI Review

The User Interface best practices are different for different kinds of systems. These requirements also vary depending on which store the application has to be published. The developers performing the code review should also consider the style guidelines associated with the UI.



Code review is an essential part of the software development lifecycle, which is often neglected. Even though it adds an extra layer of work to the lifecycle, it eventually helps build better quality software that is secure, maintainable, and scalable. It also saves the organization from potential losses at later stages.


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