This study addresses the scarcity of research examining technology's impact on learners of English as a foreign language in English for specific purposes (ESP) courses within English-medium instruction (EMI) programs. Focusing on a business communication course using a social question-answering platform, this study explores the interplay among English proficiency, motivational orientations, and online engagement. Surveying 126 university students via a mixed-method approach, this research identifies distinct motivational orientations (intrinsic, extrinsic, and self-efficacy) existing during class activities, influenced by proficiency levels, with notable differences in online participation between beginner and advanced learners. The findings suggest that while online activities enhance peer interaction and teacher feedback, they may trigger anxiety in beginners, potentially diminishing motivation and self-efficacy. These results emphasize the need to tailor technology integration to proficiency levels and motivational orientations in ESP/EMI settings. Practical recommendations are offered for educators aiming to implement effective online activities and provide targeted support, particularly for beginner learners, thereby bolstering their motivation and self-efficacy.