Exactly how are front-end and back-end testing different?

In a race for releasing high-end software products, quality and precision have become imperative to help your product stand out against the competition. Software must meet exacting quality standards. This puts the onus on software testing to deliver the best of software products.

To deliver a memorable product, an end to end testing strategy covering both the front-end testing and back-end testing is necessary. But what is front-end testing and back-end testing? And how exactly are front-end and back-end testing different?

What is front-end testing and back-end testing?

One way of breaking down the architecture of modern-day applications is to consider them as a 3-tier architecture. This comprises 3 layers, namely the presentation layer, the business logic layer, and the database layer.

Modern-day applications typically consist of a 3-tier architecture, with the presentation layer, business logic layer, and database layer. To ensure that the presentation layer provides a seamless user experience, businesses often rely on Front End Development Services and Frontend Development Services providers who specialize in developing responsive and visually appealing user interfaces. The front-end testing is largely performed on the presentation layer. In a typical web application, front-end testing would involve testing the functionality, usability, and performance using a variety of testing strategies and validation checks. In a client-server architecture, the front-end testing is done on the client side of the application.

The back-end testing is done in the business layer and the database in this 3-tier architecture. Or on the server side of the application in a client-server architecture. The business layer encompasses the business logic of the application, so back-end testing would involve checking for serious issues in the logic of the programs like the potential for corrupted data, loss of data and warped working of business rules.

Differences in the techniques of front-end and back-end testing

Since front-end testing requires checking the GUI (Graphical User Interface), the tester not only needs a good knowledge of the business requirements but should also understand how the user would interact with the system. This is necessary to be able to identify issues with the usability of the application. For example, if the tester is checking a ticket booking application, he may need to check for validations. The application must not allow numbers for entering name.

It is also important to have knowledge of automation testing techniques that can help load test the application under pressure from the users. In case of a web application, the tester must check for the load the application can withstand when accessed by users from different parts of the country or world, depending on the business requirements.

In front-end testing, the tester will also need to check the look and appearance of the application and how these come together.

Backend testing may require a deep knowledge of the underlying concepts, languages, and technologies. Unlike front-end testing, backend testing does not rely on the graphical interface but connects directly to the backend or the database for testing. Backend testing may be performed by passing data through a browser to check the desired result. A key task in backend testing will be to verify how the application works and this could involve an understanding of API (Application Programming Interface) testing techniques.

Differences in the strategies of front-end and back-end testing

Front-end testing demands a user-focused testing strategy. That apart:

• In an age of Cloud products and services, front-end testing requires a sound testing plan to test Integrations with complex SaaS services.
• The rising usage of web applications by diverse groups of customers calls for a stable user testing method.
• With applications extending to more and more devices, testing functionality and accessibility across a variety of devices becomes imperative.

Testing strategies that come under the scope of front-end testing:

• Unit testing and Integration testing
• Accessibility testing
• User testing
• Visual regression testing
• Performance/Stress testing
• Automated browser testing

Back-end testing focuses more on the functional aspects of data flow in an application and other backend components. Backend testing involves various testing checks such as data validity check, data integrity checks, performance testing, testing of stored procedures and triggers, sequence testing, and testing of the database schema, tables, keys, and indexes. Backend testing may also include server validations and checks for data duplication.

Testing strategies that come under backend testing are:

• Structural Testing
• Stress Testing
• Component Testing
• Boundary Testing

Difference in the objectives of front-end and backend testing

A comprehensive front-end testing strategy delivers the following benefits:

• A well tested front-end creates a user-friendly application.
• It creates a better clarity of the scope of the application from the user’s perspective.
• Since the focus of front-end testing is on usability issues, it helps development teams understanding the target audience.

Backend testing has the following benefits:

• It is possible to detect bugs in the early phase of application development itself.
• Backend testing allows a more detailed checking of how the application works.
• It ensures comprehensive coverage of the functionality of the application.

The primary objective of front-end testing is to render effective interactivity and display of content and data in an engaging and simple format for the user. The backend of the application is basically the brains behind the front-end. Since it includes the interfaces with the server, the application, and the database, it serves as a link between the server and the user. The backend constitutes much of the coding for the application, the quality of which will determine the effectiveness of the application. Thus back-end testing is often essential to prevent crashes, functional bugs and slow performance of the application.

Despite the differences, both front-end testing and back-end testing must come together to deliver a high-quality product.