Why is it important to understand backend testing?

Considering what exactly is behind the visual presentation of a website or application, you will definitely come across such a concept as «backend». In this article, we will look at what it is and what main aspects are related to it.  

First of all, let's define the concept of the backend.

Backend is a set of software and hardware with the help of which the logic of a website, web application, or program is implemented on the server side.

In other words, it is the internal, hidden from the user content of a website or application that is responsible for how a particular functionality will work after user actions. 

When a user searches for information on a website or registers in an app, a request is made to the server. It is from this moment the backend begins.

Even though the concept of the backend belongs to web development, it is also applied to testing. So let's take a closer look at the skills that a tester needs to have to apply for a backend tester position.

Backend and testing

We cannot say that absolutely every tester will need specific knowledge, but when it comes to backend testing, the list of knowledge usually required by employers will be longer than usual. However, it is unlikely that a new tester without prior experience with more advanced tools will be suitable for this position. The more experienced a tester is with these tools, the more chances they have to work in backend testing.

Below, we will look at the necessary backend knowledge for a tester.

However, in most cases, the list of requirements depends on the specifics of the vacancy, project, and company, so you shouldn't limit yourself solely to the list below.

The first and most obvious requirement is the theory of testing. Knowledge of key terms, methodologies, test design, and bug reports is often checked during the interview, as it is the basis for the software tester.

The next skill is the ability to work with consoles in different operating systems. The most popular are CMD, PowerShell, and Bash. It is important to know the basic commands, how to use them, and their advantages and disadvantages. 

Ability to work with HTTP and other protocols. It is often HTTP that is asked for as the main protocol of client-server architecture, but knowledge of IMAP, POP3, and SMTP may also be required if you need to test, for example, mail or even other protocols. Therefore, you should know what is behind the protocols, what network models exist, their structure, and the way they work.

As part of the protocol knowledge, the understanding of cookies, their use, and data caching are also tested.

It is important to be familiar with databases, in particular SQL, be able to create basic queries, understand their essence, and distinguish between types of DBMSs.

The next step is object-oriented programming – knowledge of principles, algorithms, and data structures. While object-oriented programming is a fairly old approach, most powerful and popular programming languages either support it or are fully based on it.

Another topic that a tester who will work with the backend should know is test automation. Perfectly, you need to know the basics of at least one programming language, such as PHP, C++, C#, Python, Ruby, JavaScript, and Java. 

It does not mean that you must know how to code and write software on the same level as a developer, but you need to be able to read the code to understand the logic of a particular part of the functionality. Such knowledge will also be useful in writing autotests.

It is important to learn the application program interfaces – OpenAPI, REST and SOAP, JSON, know the principle of web servers – Nginx, Apache, Jenkins, know how to work with popular frameworks - Django, ASP.NET core, Ruby, Node.js, have an idea of how to use GIT and GitHub version control systems and libraries.

On top of all this, an inquisitive mind and moderate curiosity are always an advantage for a tester, so versatility in skills is highly appreciated. The more testers understand such diverse concepts as described above, the easier it will be for them to test a website or application on the backend.

Why is backend testing required?

Backend testing is most often used by database testers and developers.

Often, the root of a particular error that occurs during software testing lies much deeper than we can imagine. So you need to have sufficient knowledge to find the real cause of the defect. This is where back-end testing comes in. It allows finding the root causes of software errors.

The difference between the backend and frontend

The concept of the frontend is almost always used along with the backend. This term is not the opposite of backend, as it is impossible to imagine a website or application without a frontend. In simple words, the frontend is what the user will see when using the site or application, its visual representation.

Comparing these two concepts, we can say that the backend and frontend complement each other. They are both two large areas of knowledge that are interconnected. It's hard to picture a website or an application without a graphical user interface since it's easier to interact with objects on the site when we see them. The backend is what is behind the frontend – an invisible engine, a code implementation of the website or application functionality.

Backend advantages:

1. The ease of conducting – this doesn't mean the ease of testing itself, as it requires specific knowledge, but the ability to conduct it at any time. Backend testing can be conducted both at the beginning of software development and at the end, but of course, it will be more effective at the beginning.
2. Adaptability and scalability – tests can be scaled according to the software, and test suites can be adapted to needs.
3. Improving the customer experience – since backend testing can be performed at early stages and it's mainly based on databases from the server, the number of failures will be minimized to a critically small indicator. This means that the software will receive better feedback from users, increasing its popularity and profit.
4. Absence of data loss – using backend testing guarantees that no data is lost or damaged.
5. In-depth analysis – since backend testing complements frontend testing, it works on both sides to solve problems. Backend testing provides a deeper level of verification, and in combination with other tests, such as frontend testing, it helps to ensure that the product is ready for use by real users.

Disadvantages:

1. Requires in-depth database knowledge – since backend testing is performed on the database side, the tester must have a deep understanding of this area.
2. Lack of communication – this point is more associated with the risks that may occur during backend testing. It refers to the communication between the tester and the developer.
3. Potential additional costs – backend testing is usually not only high quality but also expensive. Additional costs can result from the wrong backend testing approach, for example, when the automation process relies on a short-term perspective.
4. Using unreliable datasets for tests – often test (simulated) datasets are used for testing, and as we know, everything related to simulation does not provide a 100% or close to 100% guarantee of accuracy.

In conclusion, it's better to have a good understanding of backend testing than not. It will provide you with a decent level of competition in the testing industry since a specialist who is eager to learn new and complex things and has the ability to improve himself always is more valued.