Software Quality Assurance (SQA) Engineers play a critical role in evaluating products throughout the software development lifecycle to ensure that the outcomes of each phase and the final product possess the desired quality standards. In general, a great SQA engineer requires a different set of abilities from development engineers to effectively oversee the entire product development process. While recent empirical studies have explored the attributes of software engineers and managers, the quality assurance role is overlooked. As software quality gains increasing priority in the development cycles, both employers seeking skilled professionals and new graduates aspiring to excel in Software Quality Assurance (SQA) roles face a critical question: What makes a great SQA Engineer? To address this gap, we conducted 25 semi-structured interviews and surveyed 363 SQA engineers from diverse companies worldwide. We use the data collected from these activities to derive a comprehensive set of attributes for great SQA Engineers, categorized into five key areas: personal, social, technical, management, and decision-making attributes. Among these, curiosity, effective communication, and critical thinking emerged as defining characteristics of great SQA engineers. These findings offer valuable insights for future research with SQA practitioners, contextual considerations, and practical implications for research and practice.