It’s a polarizing question: should developers test their own code? There are plenty of arguments on both sides. In this post, we make the case that the answer is no, for a few very good reasons.

QA testing is an essential part of the software development process. It ensures that a product or feature is user-ready, and as such, is an unskippable step. But there is a divide within the tech industry about whether this step is best carried out by developers, QA testers, AI automation, or even all three.

While it may well be the most thorough option to have as many different parties as possible examine a piece of software, it is not the most time-efficient, which, when you’re rushing to finish a project, is also an important consideration.

Quality assurance engineers are trained to systematically and efficiently test for any possible bugs or weaknesses a product may have. For many reasons, oftentimes, software developers aren’t the best candidates for this job. Read on to find out what those reasons are.

What Is QA Testing?

Before we dive into the question of why developers shouldn’t test code, we’ll first tackle another equally important one: why QA testing at all? What is quality assurance testing, in practical terms? Why is it necessary, what does it entail, and what does it aim to achieve?

QA testing is, in essence, the process of definitively determining whether or not a particular feature is ready for release. In 2017, an estimated $1.7 trillion was lost worldwide due to software failures. Many of these losses could likely have been avoided if more thorough and robust quality assurance procedures had been implemented.

Quality assurance engineers don’t just carry out tests, although this is a large part of their role. They also document the testing process, suggest the best solutions to issues they find, identify KPIs for product quality, create and institute overall QA strategies, and much, much more besides.

There are many different types of tests that QA testers may perform. End-to-end (known as e2e) testing is a large part of what QA testers do. This involves mimicking real-world use of a piece of software from beginning to end to ensure everything is working as it should.

They may also perform many other different types of tests, such as load testing, which involves checking to see how much workload a system can handle at once, or usability testing, which establishes the user-friendliness of a new product.

The aim of a QA tester is always to identify any possible issues or bugs the software might have, then find the best way to correct them so that by the time it gets to the user, it can provide them with nothing but the best experience possible.

Why Developers Should Not Test Their Own Code

There is, in fact, one type of testing that is almost always carried by developers: unit testing. This involves testing specific components of a piece of software, and as it requires detailed knowledge of the code used to create it, developers often perform this task.

Now let’s look at why, in almost all other scenarios, developers testing code is not a good idea.

1. They Don’t Have Time

We’ve already illustrated all of the time-consuming and painstaking work that goes into being a successful QA tester. It requires hard work, laser-sharp focus, and most of all, dedicated time.

Now, consider all that a software developer has to do in their role. In addition to writing code, which takes up enough time in and of itself, they also have to create strategies and plans, write project documentation, liaise with stakeholders, and, of course, carry out the aforementioned unit tests.

With all of this on their plate, it’s not realistic that they could continue to do their jobs at 100% capacity and take on another difficult and time-consuming job, as well. For maximum efficiency, and so that no quality is lost, coding and QA testing should be two separate roles occupied by two different people.

2. Unconscious Bias

If you want something to be tested in a thorough manner, it is always a good idea for the tester to be somewhat impartial. This is because someone testing something they created may bring unconscious or unintentional bias into the testing process.

Software developers lack the objectivity to be able to test their own work. They may find it harder to put themselves into an end user’s shoes or assume that the user will have knowledge about something because they do. A dedicated QA tester is a neutral party that can see things in an impartial way and avoid unintentional bias when carrying out important tests.

3. Slows Down Release Times

By now we’ve established developer and QA tester are two separate jobs. Because of this, when they are carried out by the same person, they cannot be done simultaneously. Coding will have to stop to allow for testing to begin and vice versa.

This ends up slowing down workflows and negatively impacting productivity. Having a dedicated QA team ensures that when a code is ready to be tested, it will be immediately. This means that products and features can be released in a timely manner and not face delays that not only look unprofessional but could end up losing a company customers, as well.

4. QA Testers Are Specially Trained

It might be true that developers have the ability and skills necessary to carry out QA testing, but this doesn’t mean that they are the best people for the job. For all of the above reasons, but also for this one: QA testers are specially trained and skilled to do the job they do. They have experiences, backgrounds, and technical perspectives that are diverse and different from those of the developer, and as such make more efficient and competent testers.

How to Find the Best QA Testing Team

You may agree with all of these points, but lack the resources or motivation to source, recruit, and onboard a brand new team. As well as this, sometimes, developers resent in-house QA testing teams or see them as unnecessary. For these reasons, many companies choose to outsource their QA needs.

If you’d like to find a talented team of QA engineers, Number8 can help. Through staff augmentation, we enable your teams to be the very best they can be while seamlessly integrating with our nearshore professionals. Get in touch to see how Number8 can solve your QA staffing issues today.