The "Guru Penggerak" program is Indonesia's "Merdeka Belajar" initiative, aiming to enhance the quality of education by equipping teachers to implement differentiated instruction (DI). This study investigates its implementation focusing on Indonesian language teachers who have been qualified as the "Guru Penggerak." Drawing on a qualitative case study conducted in three Indonesian senior high school teachers, this research explores how teachers integrate DI across content, process, and product domains in language education. Findings reveal that teachers adeptly differentiate content by curating diverse learning materials and collaboratively establishing classroom agreements. Process differentiation entails tailoring instructional delivery to accommodate varied learning styles and readiness levels, employing specialty grouping and facilitating student engagement. Moreover, teachers differentiate product by offering multiple avenues for demonstrating learning outcomes and leveraging technology for flexible assignment submission. Through DI, teachers create inclusive and engaging learning environments, promoting deeper comprehension, critical thinking, and student autonomy. This study underscores the transformative potential of DI in language teaching, advocating for pedagogical approaches that prioritize individual student needs and foster linguistic proficiency.