Full-stack development is vital in contemporary web development, encompassing both front-end and back-end aspects of applications. In modern web development, web APIs enable applications to interact with external services and exchange data. Full-stack developers routinely engage with Web APIs across diverse programming languages, streamlining software development by encapsulating intricate code through interfaces that facilitate application connectivity. The software development landscape, particularly for web platforms, undergoes constant technological evolution. Choosing the appropriate technology for developing a Web API necessitates a comparative analysis to make well-informed decisions. Performance testing of a web API involves assessing its performance characteristics, including response time, reliability, scalability, and resource utilization. Many test batteries focus on individual components rather than the entire stack, potentially yielding misleading performance insights. This study constructed two web APIs—one utilizing .NET and the other employing Java Spring Boot. Both APIs use the same engine and database to manipulate identical data sets. A comprehensive test scenario and toolset will simulate real-world conditions, enabling the evaluation and visualization of results to facilitate performance comparison.