The main purpose of this study was to design and implement a professional development programme on technology integration for teachers in a public education centre based on the technological pedagogical content knowledge (TPACK) framework and learning by design approach, and to evaluate the programme's impact. Ten adult education teachers in a public education centre participated in this case study research. Data sources include teacher-reflective reports, lesson plans and focus group interviews. The results revealed that the programme both enhanced teachers' TPACK and influenced their teaching practices. The results emphasise the importance of providing information that aligns with teachers' specific needs in adult education centres, giving teachers an active role, making opportunities available to design technology-enhanced learning artefacts while working in collaborative teams and selecting ICT tools based on typical adult learning characteristics. The study also offers suggestions for future research and practice on the design of professional development programmes.