What Is Back-End Testing for Applications?

Many experts define back-end testing as validating the server and data processing of a web application. Back-end testing ensures the application and database layers are in sync and that they don’t display common errors, such as hanging, crashing or data corruption.

All true, but back-end testing involves much more than data and server processing verification. Back-end testing involves testing every piece that makes the entire puzzle of the app come together. For modern applications, back-end testing includes APIs, data transfer and storage, server processing, database triggers and messaging systems running code like XML or JSON — not an unsubstantial undertaking.

Let’s take a look at what back-end testing is, why it’s important, and how to implement it within an already-packed testing schedule.

What is back-end testing?

Back-end testing is verifying the systems that control application functions are secure and operate efficiently and effectively. Well-running back-end systems make the application front end useful.

Testing the UI, or front end of an application, ensures customer workflows and scenarios function properly. Testing the back-end systems verifies that it all runs together without interruption.

Think of back-end testing like the skeletal structure of a human being. A person’s exterior is vitally important, but the bones and muscles hold the human body together and are fundamental to any bodily function. Without a skeleton and muscular system, the human body becomes a dysfunctional blob. The same applies to an application that fails users because the back-end system malfunctions — hence the need for back-end testing.

Why is back-end testing often ignored?

Back-end testing is essential to prove the system works across the board. Back-end testing ensures the application functions for all customer scenarios without generating surprise errors or crashes. Yet, the importance of back-end testing is often not recognized by the organization as a whole.

Organizations that skip or ignore back-end testing typically do so for one of these three reasons:

• time

• tools

• education or knowledge

Developers are often tasked with coding, designing and developing a complex integrated network infrastructure that also must be secure. On top of that, they must follow a set of standards, design principles and architectural structures. Because developers create this beast, the rest of the organization assumes they also test it.

Most developers test what they can under tight deadlines to deliver working code on time and on budget. But just because code works on a QA test system doesn’t mean it’ll work for customers. Systems vary, and test servers have a tendency, in most software development organizations, to be nothing like the production server. What you see in the UI is not necessarily what the customer will get. Other issues occur too, such as data corruption in the database or messages being rejected due to bad data, but all the user sees is an error message or invalid information displayed.

Expect customer frustration when an application displays invalid data or fails to save edits. Data issues alone cause many high-priority or critical defects reported by customers. Application crashes and severe failures frequently come down to preventable server and data processing failures.

How can we prioritize back-end testing?

How does a testing team ensure there is enough time allotted to fully test the back end? The first step is convincing the team that back-end testing is the most important testing initiative. All of an application's critical functions use the back end. Modern applications don’t function without a quality, working back-end system.

Start the test plan with back-end functional testing, and then move into UI testing. Another option is to assign a tester or two to perform back-end testing while the rest of the team continues front-end testing. Experiment and see where the more critical defects are detected.

Pre-planning for back-end testing is necessary because testers need access to servers and databases. Access might require temporary security codes or IT assistance. Additionally, testers might need developers familiar with messaging systems and database structures to answer questions or review issues. Team collaboration is key for any software development team, and this is no different with back-end testing.

Effective back-end testing also provides knowledge of how the system operates from end to end. There’s no other way to fully test and understand application functionality without knowing how the back-end systems connect and function. The testing team’s expertise and knowledge increase exponentially with back-end testing.

How can we implement effective back-end testing?

The simplest way to implement back-end testing is to collaborate with developers who designed or maintain:

• APIs

• databases

• messaging systems

• server processing

You might find one or more developers who are willing to train testers on how to test back-end systems. If not, work alongside developers and allow time for testers to create a testing checklist.

The first step is understanding which back-end systems can be tested and to what extent. Back-end testing involves developing an understanding of how to test:

• database schema

• database tables and columns

• keys and indexes

• software triggers and how to action them

• data type and structure requirements

• API endpoints

• data movement between the application, database and other integrated applications

• messaging systems and how to view XML and JSON

• the UI to exercise all back-end processing

A sample back-end testing checklist might include:

• Database tables

  • Verify schema

• Database columns

  • Verify columns and linkages

• Database keys

• Database indexes

• Trigger all database triggers

  • Confirm the actions that occur are valid

• Validate data type and structures

• Confirm the database does not contain junk or invalid data types or structures

• Test all API endpoints

  • Access

  • Security

  • Error handling

• Test API functionality

  • Valid

  • Error handling

  • Security

• Verify data messaging for valid data

• Confirm all UI actions trigger the appropriate back-end system

• Review server logs for possible issues

Next, consider how to use existing development tools to view processes, messages and data — these existing tools save money and make it easier for testers to train in-house. Most development tools enable team members to view databases without making changes, execute APIs and validate data transfer. Many tools also enable users to view incoming and outgoing messages.

Back-end testing identifies defects that cause critical failures that go unseen in the UI. Additionally, it prevents the software development team from constantly losing time to preventable hotfixes. If you’ve ever been on a team that had to constantly manage one hotfix or software patch after another, you understand the time it wastes and its negative effect across the organization. Take the time to test the back end, leveraging existing development tools that help the team perform the task. You’ll build positive vibes with employees and customers while adding to the business’s bottom line.