Technical deep dive

Optimizing modern software testing strategies with better test data

Author
Chiara Colombi
Author
February 28, 2025
Optimizing modern software testing strategies with better test data

According to the Redgate 2019 State of Database DevOps report, 65% of companies use production data for testing, and only 35% use masking techniques. The cybersecurity risk for these scenarios is significant, highlighting the importance of proper test data management. Meanwhile, as software becomes more complex with multiple layers and subsystems, the need for quality data rises in tandem. Quality data is essential to ensure all components work together as expected. This guide will discuss some modern testing strategies and the importance of quality test data to ensure proper test coverage.

How test data is used in software testing and development

Test data influences everything from code validation to system performance under real-world conditions. The right test data ensures that applications function correctly, perform efficiently, and remain secure before reaching production. Different software testing strategies rely on test data in unique ways, depending on the scope and intent of the tests being performed.

Test data for white box testing

White box testing relies on test data that interacts directly with an application’s internal logic, allowing developers to analyze code execution paths, decision structures, and potential flaws. This type of testing requires carefully crafted test data that exercises every part of the codebase.

  • Structural validation: Test data ensures every condition, loop, and function executes correctly.
  • Edge case identification: Specific test data helps uncover unexpected failures in less common execution paths.
  • Fault injection: Test data can be designed to trigger failures, allowing teams to evaluate how well an application handles errors and exceptions.

White box testing also benefits from mutation testing, where small changes are introduced to the code, and test data is used to determine if the existing test suite catches those changes. This approach improves the resilience of test cases by highlighting weak spots in the testing process.

Generating effective synthetic test data for white box testing often involves code analysis tools that generate inputs dynamically, ensuring comprehensive coverage without unnecessary manual effort. These improvements align with modern software testing strategies that emphasize efficiency and test automation.

Test data for performance testing

Performance testing simulates real-world loads to measure an application's responsiveness, stability, and scalability under specific conditions. Simply flooding a system with requests isn’t enough—effective test data must account for realistic user interactions and system constraints.

  • Simulated production loads: Test data should mimic actual traffic patterns, including peak and off-peak usage.
  • Data variability: Using diverse data sets helps uncover performance issues tied to specific inputs.
  • Resource contention testing: Proper test data ensures that high-traffic scenarios do not degrade performance for concurrent users.

Test data should reflect authentic usage scenarios so engineers can identify slow queries, resource bottlenecks, and caching inefficiencies before they impact real users. Additionally, performance test data should include datasets of different sizes to measure how scalability issues arise when data volume increases. This exposes inefficiencies in indexing, storage access, and memory management.

Another critical factor is endurance testing—evaluating how systems perform over extended periods with sustained traffic. Many applications pass short-term load tests but degrade over time due to memory leaks, inefficient garbage collection, or database fragmentation.

Well-designed test data allows teams to simulate these long-running conditions and make appropriate adjustments to the code. Implementing strong test data management practices improves the reliability of software testing strategies focused on system longevity.

Test data for security testing

Software testing strategies that prioritize security testing require dynamic, adaptable test data to stay ahead of emerging threats. Unlike performance testing, where inputs are expected to follow normal user behaviors, security test data must be deliberately crafted to break the system and expose weaknesses.

  • Injection attack simulations: Test data should include payloads designed to trigger SQL injection, cross-site scripting (XSS), and other common vulnerabilities.
  • Access control validation: Role-based test data ensures that users can only access data and functionality they are authorized to.
  • Fuzzing for unexpected behavior: Randomized test data helps identify security flaws by introducing unpredictable inputs that might cause crashes or leaks.

Effective security test data should not only test known vulnerabilities but also stress test authentication mechanisms and data validation processes to uncover hidden risks. In addition, security testing should involve session hijacking simulations where test data replicates stolen session tokens or expired credentials to validate whether unauthorized access can occur.

Credential stuffing and brute force attack testing are also incredibly important. By generating large sets of randomized usernames and passwords, security teams can test an application’s ability to detect and prevent automated login attempts. This helps evaluate the effectiveness of rate-limiting mechanisms, multi-factor authentication enforcement, and anomaly detection in login systems.

Test data for black box testing

Black box testing focuses on how an application behaves under different conditions without looking at its internal code. Test data is key to ensuring all possible user interactions are covered, revealing inconsistencies, logic errors, and UI issues.

  • Functional validation: Test data verifies that inputs produce expected outputs across different scenarios.
  • Error handling assessment: Unexpected or malformed test data helps confirm whether the application responds appropriately to invalid inputs.
  • Localization testing: Test data should include different languages, date formats, and currency types for a globalized user experience.

Comprehensive software testing strategies that prioritize security testing require dynamic, adaptable test data to stay ahead of emerging threats. Test data for black box testing must cover normal usage as well as edge cases so the software meets user expectations in any environment. Additionally, test data should include accessibility-specific inputs, such as screen reader-compatible text and different color contrast settings, to validate that the application meets accessibility compliance standards.

The evolution of software testing strategies

Companies are embracing continuous integration and delivery to meet market demand and provide customers with exceptional digital experiences. The need for speed is key. But traditional monolithic applications significantly hinder the process. These applications rely on tightly coupled components that are hard to test in isolation and make the application very fragile. In other words, a change in one component will likely have significant impacts on every other area of the system. 

The service-based application architecture evolved out of a need to de-couple application components to eliminate code fragility and allow for more rigorous component testing without negatively affecting other areas. This new approach requires strategies to ensure that every layer of the system works as expected and interfaces correctly with any third-party systems. 

These new strategies are categorized into “buckets” that indicate the level of granularity required at each stage. The stages are often referred to as the testing pyramid and form the basis of the entire test suite for an application.

Unit testing

The Unit test, at the bottom of the pyramid, is the most granular test one can perform. The test is used to validate small chunks of code, typically a single function. It is a white box technique developers perform during coding to isolate functions and rigorously test them to ensure they work properly. Isolating functions in this way helps identify unnecessary dependencies between the unit being tested and other components of the system. Several tools are available to assist with this type of validation, such as JUnit, PHPUnit and JMockit.

Integration testing

After verifying that each isolated unit works as expected, the next step is to ensure that these units work as expected when grouped. The goal at this stage is to expose defects in the interfaces and integrations between components. Selenium, JUnit, Mockito and AssertJ are just a few examples of tools used for this type of evaluation.

Contract testing

With the evolution of service-based architecture, testing the service endpoints and verifying that the API works as outlined becomes crucial. This type of verification tests each interaction scenario with the API endpoint using tools like Apache JMeter, Jaeger or HoverFly.

UI testing

The user interface is the customer's first impression of the application. Whether or not the system works won't matter if it isn’t user-friendly. UI verification checks to ensure that the visual elements work as expected and allow the user to accomplish the tasks they need to perform. These types of tests include all user actions carried out via the keyboard, mouse or other input devices. They also check to ensure all UI elements display correctly. A few standard tools for performing UI tests include Katalon, Selenium IDE and Testim.

End-to-end testing

As the name indicates, end-to-end testing is a technique that validates the entire application from beginning to end to ensure that it works properly. The purpose is to evaluate the entire system for dependencies, data integrity, and interfaces to databases or other systems in a production-like scenario. Cypress, Cucumber and Selenium are a few of the tools often used at this stage.

Acceptance testing

The true indicator of success is whether the application meets the user’s needs as defined in the requirements. This stage is where actual end-users work in the system performing real-world scenarios to evaluate the system. 

Exploratory testing

It is not always possible to come up with every scenario when planning test cases. According to TechBeacon, “Exceptional and experienced testers have an instinctive manner in which they find defects.” Therefore, it is instinct, experience and knowledge that helps testers explore and uncover defects that may not have been otherwise detected.

The importance of test data management

Testing is only half the battle. Generating optimal test data can decrease ramp-up time to begin system validation and increase the likelihood of detecting bugs by relying on data that closely resembles production.

Another significant importance of having appropriate data generation is to ensure compliance with GDPR. Using advanced de-identification and anonymization techniques can help ensure your company does not unintentionally violate privacy laws. 

Effective test data management leverages solutions for data de-identification, data generation, database subsetting, and streamlined data provisioning to equip developers with the up-to-date, realistic, and targeted data they need to drive forward product innovation. Quality testing simply cannot happen without quality test data.

Test data management with Tonic.ai

Tonic Structural automates the de-identification, generation, subsetting, and delivery of high-quality, production-like data. Built to integrate directly into development workflows, Structural ensures that teams always have high-quality, production-like test data, without the security risks of using raw production data.

  • Accelerate development and testing: Shorten development cycles and speed up QA by providing fast, reliable access to realistic test data.
  • Enable shift-left testing: Improve early-stage bug detection and optimize product development with high-quality test data available from the start.
  • Ensure regulatory compliance: Enforce security policies within test data generation to reduce risk in lower environments and meet compliance standards.
  • Unblock off-shore teams: Provide synthetic test data that is safe, accessible, and useful, ensuring distributed teams have the resources they need.

Modern software testing strategies rely on effective test data management to drive faster release cycles, enhance security, and support large-scale automation. Tonic.ai helps you strengthen your staging environments with useful, realistic, safe data created from your production data. Using this data to hydrate all of your lower environments can help shorten sprints and deploy releases up to five times faster. Request a demo to learn how we can help enhance your test suite. 

Chiara Colombi
Director of Product Marketing
A bilingual wordsmith dedicated to the art of engineering with words, Chiara has over a decade of experience supporting corporate communications at multi-national companies. She once translated for the Pope; it has more overlap with translating for developers than you might think.

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