What Is a Code Review and Why Do You Need It?

Building a startup is hard; building software for it is not any easier. What makes software great? Good code. But how can you be sure that the code is good?

Working with many clients who came to us with software samples they would like to develop, we found out that, apparently, many freelance developers and even IT companies ignore the process of code review. Since we in Altamira consider the code review stage to be a basic service, we decided to explain our perspective.

So let’s start with the basic terminology.

What Is Code Review?

Definition: Code review is a systematic examination of software source code, intended to find bugs and estimate the code quality.

The code review process contains the following stages:

• Best practice - identifying more efficient ways of completing any task
• Error detection - finding logical errors
• Vulnerability exposure - identifying the most common vulnerabilities
• Malware discovery - a special kind of code review used to detect suspicious pieces of code or to find the back-doors and any malware integrated into the software

Why Do You Need Code Review?

There are several reasons why doing a code review is a necessary part of development.

The first reason is to reduce risks. For example, if you have some software that was coded by a freelancer or an agency but you are not sure of the quality of the work because even good developers can miss something. Double-checking is always a good idea.

Moreover, while working together on examining the code, every team member can suggest smarter solutions that would improve the general performance of the project.

The main thing you need to remember about code review is that it should be performed BEFORE your new development team takes on a new codebase or project. Checking the code before starting a project gives your team the chance to get familiar with it and to determine whether the code is clean or requires any rework.

Code Review Checklist:

Having a lot of practice in reviewing code, we decided to prepare a small guideline for developers who are going to check the source code for their projects.

1. Divide the Review Into Time Slots 

Don’t try to review the whole project at once. Experts advise not to review more than 400 lines of code at once. Moreover, a single check should take no more than an hour. The reason is humans cannot effectively process that amount of information, especially over such a long period of time. When you try to go beyond this mark, the ability to detect bugs decreases notably, so you might miss some crucial errors.

2. Ask Teammates for Help

Two heads are better than one. You might be surprised how the quality of the review increases when you share this process with someone else. We are used to performing the collaborative code review using Crucible by Atlassian. This tool allows you to assign reviewers from across your team, and discuss the chosen lines of source code, files, or an entire changeset. We can also track and report the parts of the code that have now been reviewed yet. Collaborative code review not only enhanced the code itself but also the level of the team's expertise due to sharing knowledge while discussing changes.

3. Capture Metrics

Before starting the review, the team should set precise goals; for example, to “reduce the percentage of defects in half.” The goal “to find more bugs” is not clear, so it’s impossible to reach. Besides setting goals, capture such metrics as the speed of performing the review, the number of bugs found per hour, and the average number of bugs per code line. Constant tracking of review performance will show you the real picture of your inner processes.

4. Stay Positive

Code review can sometimes put a strain on the relationships within the team. Nobody likes to be criticized, so it’s very important to keep a friendly atmosphere unless you want your coworkers to lose their motivation. Instead of perceiving each and every bug negatively, think positively, as they are new opportunities for improving the code quality in general.

5. Set Up the Bug Fixing Process

So your team provided the code review of the whole process, but how about fixing all those bugs that were found? It was a pure surprise for us, but not all the development teams actually have established a method for fixing bugs that they find. Fortunately, we use the collaborative method, not only to discover bugs and errors but also to fix them. All the bugs are discussed with the creator (except for situations when we review another team’s code), and all the changes are always approved before submission into the source code.

Code Review: The Benefits

1. Consistency in Design and Implementation

It is detrimental to collaboration and hinders progress if developers keep following their own coding style during development.

The code review process requires developers to adhere to certain coding practices during the Sprint developer phase. This standardization of the source code makes it easy for everyone, even new developers, to understand and study it.

As team members change their projects, code review can be very useful. Future developers will be able to spend more time developing new features than analyzing existing code if they follow a consistent coding style.

2. Optimizing Code for Better Performance

They gain valuable feedback from senior developers, which helps them to improve their code skills. It also helps to identify errors or critical mistakes that could eventually lead to serious bugs.

These mistakes can be eliminated before the code review moves on to the next step. A fresh pair of eyes will review each unit. If errors are found, the reviewer will correct them.

3. Collaboration and Sharing of New Techniques

Programmers tend to spend most of their time coding alone. However, practices like code review enforce developer collaborations. This encourages developers and coders to exchange ideas and interact about their code. It fosters trust between developers.

Team members can also exchange information about new learnings during code reviews. Code review allows team members to improve their skills and learn about the latest technologies.

4. Monitoring the Project’s Quality and Ensuring That It Meets All Requirements

Every developer creates his or her own features based on requirements. There is a chance that a developer might misinterpret a request and end up creating a feature that doesn't work.

This helps to address such situations as code review validates the feature against the expected feature. This is a validation of the features that have been developed. Code review helps to ensure that there is no misinterpretation of the requirements or scope.

Wrapping Things Up

Providing code review must be an essential process in any web development company, as it helps to maintain high-quality coding standards. Working together on code analysis brings the team together and gives the opportunity to share knowledge and experience within the company.

If you run a startup and you decided to hand over the project to another team, always request a code review in order to get the best quality software in the end.