Beneath the Surface- Log Analysis, Errors, and Their Role in QA

Ready for a quick dive?

Every advanced system is like an iceberg—what users see is only the tip. Beneath the surface, complex processes take place, and logs document every part of that journey.

In QA, logs serve as a crucial tool for understanding what really happened, whether everything seems fine, or something went wrong.

A log is a record of every action a system performs, from user requests to interactions between system components, every process starts with a client request.

Logs document everything that happens in between: API calls, database queries, authentication checks, and more, while the user only sees the result, the real story is captured in the logs.

Logs provide a complete picture of the system’s behavior, showing what worked, what didn’t, and where potential issues may arise.

In QA, logs are more than just a tool for understanding processes on the server side or how diverse services interact. Logs serve as documented proof of errors when opening a bug report and provide valuable insight into the source of the error, often holding the key to solving it.

Logs record thousands of actions every moment, a professional tester must know what to look for and where to find it.

Errors – Why Do We Want Them?

An error ≠ a failure

Not every error is a bug. Sometimes, errors are expected and even necessary—for both the user and the system. Errors ensure that the system behaves as expected by preventing invalid actions and providing appropriate feedback.

For example, a failed login attempt with incorrect credentials should trigger an authentication error—classic, right?

But why errors important for the user, and why is it important for us as testers that it is important for the user?

Ever experienced clicking a button repeatedly, and nothing happens? frustrating, isn’t it?!

In such cases, the user experience is flawed, the system may seem unreliable because the user left without any indication of whether the button worked or not, the request received or not, the service was available or not, or any other error occurred.

Therefore, as testers, we want to make sure that errors are effectively managed for every scenario, and that they appear when they should. Providing clear error feedback improves product quality, makes the system user-friendly, and enhances the overall user experience.

So, When Is an Error Problematic?

When an error appears in the logs without clear feedback for the user, as in the example above, the user left in the dark, which can harm trust in the product.

Or

When an error indicates a communication failure between system components. This could point to deeper, more complex system issues.

Logs & Errors –the Connection

Logs help testers pinpoint the origin of an error, whether it’s an API issue, a database failure, an authentication and more.

When a bug is discovered, logs provide essential insights into what went wrong. By analyzing the logs, testers can recreate the bug scenario and identify exactly where the process broke down.

Logs also help testers differentiate between errors that are expected and those that point to real malfunctions.

Log analysis is an integral part of high-quality QA processes. It allows testers to deeply understand system behavior, detect hidden issues, and distinguish between errors that indicate proper functionality and those signaling real problems.

When QA testers expert log analysis, they don’t just find bugs—they gain a comprehensive understanding of the system, improving product quality and improve the user experience.