This book is about how teachers can continue with their professional development as language teachers once their period of formal training is over. It also examines how supervisors and administrators can provide opportunities for such development to take place. The need for ongoing teacher education has been a recurring theme in language teaching circles in recent years and has been given renewed focus as a result of the emergence of teacher-led initiatives such as action research, reflective teaching, and team teaching. Opportunities for in-service training are crucial to the longterm development of teachers as well as for the long-term success of the programs in which they work. The need for ongoing renewal of professional skills and knowledge is not a reflection of inadequate training but simply a response to the fact that not everything teachers need to know can be provided at pre-service level, as well as the fact that the knowledge base of teaching constantly changes. This book also discusses the importance of digital literacy for pre-service teachers in the 4.0 era since many teachers of English candidate are still digitally illiterate in the local context. The touch of some social media and learning platform in this books is expected to aware the teachers candidates to update and upgrade their capacity.