eng Science and Education Publishing Journal of Computer Sciences and Applications 2328-725X 2025-10-22 13 1 37 40 10.12691/jcsa-13-1-4 JCSA20251314 article Jafar Inamdar Corresponding author: jafar.inamdar@gmail.com 1 Software Development and Test Engineer, Pittsburgh, USA This document explores the significance of parallel testing in identifying concurrency issues within APIs and proposes the utilization of TestNG framework to facilitate efficient parallel testing. Concurrency issues, often elusive and challenging to detect, can cause critical failures in API systems under high loads. Traditional sequential testing methods may fail to uncover these issues adequately. Parallel testing, when implemented effectively using TestNG, can significantly enhance the detection of concurrency-related defects in APIs. https://pubs.sciepub.com/jcsa/13/1/4/jcsa-13-1-4.pdf Java TestNG Concurrency