Agile methodologies have revolutionized software development, impacting traditional software testing. This paper focuses on the efficiency of different testing approaches in the use of agile development models, with the aim of presenting quality assurance in the development processes that use numerous iterations. To achieve this, we integrated a systematic review involving 87 peer-reviewed articles along with a survey based on 15 software development teams across different industries. In this research, a thematic analysis of the collected qualitative data, along with an assessment of quantitative measures of testing practices in an agile environment, was conducted. Based on the findings, it is identified that the achievement of agile testing techniques and approaches is associated with the integration, automation, and collaboration of the testing team and developers. The teams that adopted these approaches increased their defect diagnosis by 35% and reduced their time-to-market by 28%. The study also shows that TDD/BDD results in better quality code and increased productivity for the team in agile projects. Thus, we can state that agile testing needs to transition from sequential, phase-based testing to an integrated, lifecycle-based model of testing. This transition necessitates not only the integration of new technologies but also a new culture in the development teams. The findings of this research will be beneficial to organizations looking to improve their strategies for implementing testing activities in agile systems with the aim of improving the quality of the software being developed while at the same time shortening the delivery time.