Since its inception in the early 1960s, English for specific purposes (ESP) has been characterised as a materials-driven and a teacher-led movement. Distinctively separated from general English teaching, ESP teachers often function as designers and implementers in curriculum development. Attaining a certain degree of disciplinary expertise is the greatest challenge that they encounter while transitioning from general to specific language teaching. Recognising a dearth of research on ESP teacher development, this study has emerged from in-depth, unstructured interviews conducted with both novice and expert educators. This qualitative inquiry examines the collaborative strategies employed and hurdles encountered by ESP educators within the tertiary education arena, with a specific emphasis on their vital contributions to the English language instruction of undergraduate students in India. The findings offer insights into the evolving specificity of English language education in India, particularly for educators and institutions committed to improving language teaching practices in higher education.