Regression defects, which occur when a software bug fix inadvertently causes other issues in the application, pose significant challenges in software development, particularly in terms of project cost, time complexity, and maintenance. These defects necessitate regular regression testing to ensure that bug fixes do not disrupt the application's intended functionality. Effective strategies for handling regression defects include thorough code reviews, monitoring metrics, integrating Shift-Left testing with continuous testing, and automating testing processes to enhance speed and accuracy. Prioritizing and categorizing test cases, ensuring efficient time management, and maintaining sufficient budgets are crucial for minimizing regression defects. Additionally, involving the entire team in reviews, setting entry and exit criteria, and using exploratory testing can further optimize the testing process and improve software quality. Despite being repetitive and sometimes tedious, addressing regression defects is vital for delivering robust software products and meeting stakeholder expectations.