Together with the rapid growth of blended courses implemented in higher education, instructors and researchers are keen on exploring the efficient models of blended learning (BL) to enhance students' achievement. While many BL theoretical models exist, robust empirical evidence confirming instructors' strategies and implementation is still scarce, particularly the possible differences as a function of disciplines. To address this lack of evidence, a qualitative study was conducted among 29 instructors in a large public university in Vietnam. Employing the Content-Construction-Communication framework as the guiding lens, the present study conducted semi-structured interviews to capture how instructors in hard and soft disciplines designed and implemented their blended courses. The findings revealed that instructors from hard and soft sciences shared both similarities and differences in their instructional strategies. Similar aspects included the alignment of course objectives with learning activities design and assessment, recognition of the importance of students' individual learning and collaborative learning, and responsiveness regarding students' questions. Yet, differences were observed in the design of both individual and collaborative online activities and instructors' online facilitation. Thus, the results provide a clear picture of different BL designs, which can be helpful for instructional designers and policies aimed at professional development support for successful BL implementation.