摘要:In Sweden, upper secondary school teachers made a swift transition into emergency remote teaching in 2020 due to the outbreak of covid-19. This paper reports on a Design-Based Research intervention in which professional development was designed using the Blended Learning Adoption framework, to support teachers to develop their teaching practices online. Twenty-six teachers participated in the intervention which spanned six months. Data was analysed using thematic analysis. Key results revealed that the pandemic had become an impetus for change, for many teachers, but far from all. Emerging teaching practices in synchronous online learning included: inviting special needs pedagogues in parallel breakout rooms, and grouping and re-grouping students when facilitating varied collaboration. Apart from realising new potentials of online teaching and learning, teachers identified emerging challenges such as: new ways of cheating, ethical aspects of accessing students’ private homes via cameras and a lack of guidelines on managing disengagement. Conclusively, teacher’s professional development and new experiences elicit new practices that could benefit teachers after the pandemic. Professional development during uncertain times and design principles supporting intervention ownership transfer are discussed.