Full-Stack Testing: A Comprehensive Overview

If you are in the information technology industry then you're probably familiar with full stack development, which essentially covers the entire procedure of creating an application software from front-end to back-end. Full-stack testing, on the other hand, involves testing all layers of the software to make sure everything works seamlessly and ensure end-to-end software quality. 

In this comprehensive overview, we will break down why full-stack testing is important, where to start, which testing types to use, and possible challenges you might face along the way. 

What is full-stack testing? 

The digital world is evolving at an exceptionally fast pace. According to statistics, over a thousand applications are released in both Google Play and the Apple App Store every day. One way to stand out in this competitive market would be to focus on quality and deliver software that fulfills or maybe even exceeds user expectations. By providing a quality product and seamless user experience to a client, you also earn their loyalty—and loyal customers usually tend to keep coming back to use the product. 

One way to achieve quality software is by implementing a full-stack testing approach, which is an extensive testing method that covers every layer of the application from the user interface to the backend systems and everything in between. It guarantees thorough functionality coverage of the application, pinpoints integration issues, assures performance, evaluates the security of the app and improves user experience, resulting in a more stable product. 

Where should you begin with full-stack testing? 

When talking about full-stack testing and testing in general it’s important to start as early as possible. One of the seven testing principles states that early testing saves time and money, so testing definitely has its benefits. Therefore, in order to identify issues early on, it’s important to begin testing as soon as the software development process begins. Early testing is often referred to as shift-left testing. 

The phrase “shift-left testing” describes the method of moving testing activities earlier in the project timeline and incorporating it at the beginning stages of the software development life cycle. For instance, this approach is different from the sequential “waterfall” model, which separates testing into a separate phase that happens after the development process. With the shift-left approach, testing is ongoing and happens alongside development with implementing continuous quality checks from the planning phase and maintaining those checks during the development phase.

What are the benefits of the shift-left testing approach? 

Shift-left testing allows you to detect potential issues early and mitigate the risks of finding and fixing those issues in a later stage of the development life cycle. Faster feedback makes it easier to identify gaps in design functionalities and allows you to make continuous improvements throughout the development process. 

What testing skills are necessary for full-stack testing?

Testing the entire application stack requires a deep understanding of the software development lifecycle, programming, test automation and various testing methodologies. Therefore, full-stack testing allows the whole team to collaborate depending on the experience and expertise they have. 

Let’s take a closer look at the testing types that are essential when implementing a full-stack testing approach. Keep in mind that the specific testing types may vary depending on the project. 

1. Continuous testing 

Continuous testing is a practice which involves integrating automated quality checks throughout the development cycle to provide continuous feedback on quality and address issues as soon as possible. Without a consistent feedback loop, issues could go undetected for a long period of time and potentially spread into a more complex code, making it more difficult to fix.

2. Exploratory testing 

Exploratory testing is often considered as being identical to manual testing, however, they have rather different focuses. When implementing manual testing, the aim is usually to verify a set of predefined requirements against an actual behavior, whereas exploratory testing focuses on “exploring” the unknown. 

Exploratory testing relies heavily on the software tester’s experience, analytical mindset, and creativity to come up with different real life scenarios to observe the applications behavior under test. Exploratory testing can be beneficial to combine with other testing techniques since it can detect edge cases and usability issues that other more structured testing approaches might miss. 

3. Data testing

Data testing is used to validate the accuracy, completeness and consistency of the data. It is particularly important since most companies process and store data in their systems. 

On the 25th of May, 2018, the  General Data Protection Regulation (GDPR) came into effect. This directive outlines how data should be handled. It sets the standards to guarantee that personal data is handled in a lawful, clear and safe manner. Conducting data testing is essential to adhere to GDPR regulations, helping companies avoid any penalties or legal consequences for ignoring or failing to meet the directive’s requirements. 

4. Visual testing 

The look and feel of an application shapes a customer’s first impression. When the design and user experience are appealing, users are more likely to engage further with it. Therefore, it’s crucial to ensure that users find the application’s visual experience both seamless and enjoyable by performing visual testing. 

With visual testing we are able to verify whether the application under test matches the expected design, including the size, color and placement of each component. Key aspects of visual testing include layout validation, consistency in appearance, and responsive design testing. 

5. Performance testing 

Performance testing is a type of software testing for evaluating how a certain software performs under different conditions. According to research on website response times, users often abandon websites after just a 10-second response time delay. This highlights the importance of maintaining performance levels that meet user expectations, as poor performance could lead to financial loss. 

Evaluating or testing app performance requires collecting various key performance indicators (KPIs). Tracking these consistently during development will assist the team in making earlier adjustments and determine if the system meets the necessary performance standards. Common KPIs that are being often monitored are response time, concurrency and availability. 

6. Security testing

In recent years cyber attacks and data breaches have gotten a lot of broadcast in the media and according to statistics they are vastly growing in number. In fact, according to the 2023 Data Breach Report by ITRC shows that the total number of compromises in 2023 has almost doubled in comparison to the previous year. As a result, it is essential that security measures are taken into account at every phase of the software development process. The aim of security testing is essentially to find and assess the weaknesses of the system. This allows teams to act fast to make adjustments and prevent potential issues or hacker attacks before they arise. 

7. Accessibility testing 

Accessibility testing involves evaluating an application to ensure that it is accessible and usable by individuals with different types of disabilities. In order to do so, testers should first understand accessibility standards required by law, such as the European Accessibility Act (EAA) and accessibility guidelines like the Web Content Accessibility Guidelines (WCAG). Both manual testing and automated testing can be used to verify that these standards are met. 

The main goal of accessibility testing is to make sure that all users can engage with the application without obstacles. Failing to do so could lead to lawsuits, fines and bad reputation.

Read our report—Digital Accessibility & EAA: Telecommunications Industry Under Review—to learn more about digital accessibility and the EAA.  

8. Mobile app testing 

Mobile usage has steadily outpaced desktop usage for years. For example, if we look at data from July 2023 to July 2024, mobile devices accounted for around 60% of global usage, compared to 40% for desktops. This makes it critical to evaluate mobile apps and ensure that websites function smoothly across a range of mobile devices.

Before starting with the testing process, it is important to gather the requirements and understand the testing goal. From a product and business perspective, it would be beneficial to gain an understanding of the target customer and the primary devices they use. This approach is valuable for comprehending the scope of testing and to select the necessary devices. It’s key to include devices with different operating systems, screen sizes, and hardware to verify functionality, compatibility, network connectivity, usability, and performance. 

What are the possible challenges of full-stack testing?

• Finding people with necessary skills. As mentioned earlier, full-stack testing requires a wide range of expertise and skills which can mean extra costs in terms of hiring, onboarding, and training. A way to solve this challenge is to consider QAaaS.
• Team collaboration. Testing activities will likely be shared among multiple people. This could lead to an unequal distribution of workload, which may cause tensions within the team. To avoid such situations, it’s important to encourage effective communication within QA teams.
• Large testing scope. Since testing activities include both front-end and back-end layers, the complexity and test maintenance can spiral out of control as the software evolves. To manage the growing scope, break down tests into smaller, independent units that focus on specific components of the application. Use test automation to handle repetitive tasks and prioritize tests based on critical features. 

The bottom line 

Full-stack testing is an effective way to ensure high-quality software. By adopting a shift-left methodology and moving testing activities to the early stages of the software development life cycle, you are able to identify and resolve issues earlier, often with lower costs and less effort. Putting together a thorough testing strategy takes time and dedication, but the advantages, like faster feedback, earlier issue detection and improved overall quality makes it a valuable investment. 

Ready to see the benefits of full-stack testing? Contact us to learn more about our quality assurance services and how we can help take your software to the next level.