Software testing is crucial for ensuring the sustainability, correctness, and reliability of a system. Through properly implemented tests, potential errors can be identified and fixed in the early stages of development, thus reducing maintenance costs and improving the quality of the final solution. The benefits of testing are numerous – from ensuring system stability, to increasing confidence in the correctness of the code, and enabling safe updates without disrupting existing functionalities. Correct and consistent testing makes it possible to achieve a high level of security in system operation, thereby improving the overall development process. For testing to be effective, it is important to ensure that all necessary tests are present and correctly written. In this context, the Test-Driven Development (TDD) approach represents a good practice that enables a systematic workflow in which tests are written before the actual implementation of functionality. This way not only is code coverage ensured by tests, but it also promotes the development of modular, readable, and maintainable software. The practical application of test-driven development is illustrated in the Innovation module within the Croatian Research Information System (CroRIS). The methodology is implemented through clearly defined development steps, ensuring high test coverage and high-quality software code.