The article presents research findings on the professional growth of three in-service EFL teachers from Germany who took part in a teacher education programme centred on technology-mediated plurilingual education. The study investigated how the programme influenced the development of the teachers' pedagogical and digital skills in creating and executing plurilingual-inspired virtual exchanges. The programme took place over the course of an academic year (2021-2022) and was divided into three phases, including a four-week virtual exchange with other participants, self-study through an online course, and pedagogical assistance for executing virtual exchanges in teachers' schools. The research employed a case study approach, and data were collected through classroom observations and field notes, recordings of teacher reflective activities, as well as focus group and individual interviews with teachers. The findings indicate that the professional development programme prompted teachers to reconsider their language ideologies and question policies and approaches that emphasised monolingualism in their particular settings. These included practices like separating languages in bilingual programmes, prioritising the native-speaker model as the ultimate goal of second language acquisition, and school policies that ignored the educational requirements of students from diverse linguistic and cultural backgrounds.