In the online implementation of immigrant integration training, there are areas that receive limited attention in the pedagogical studies of Finnish language and literature subject teachers. Using the Design Science Research method, an artifact of socially significant online integration training is studied. By participating in the evaluation and development of the design of this artifact, teacher students also contribute to the design of a meta-artifact. The results can be used to create a micro-credential for teacher training, enhancing teachers' abilities to work in online training programs that promote the integration of adult immigrants. The outcomes of collaborative development provide additional insights into the development needs of educational technology and the intersections of technological and pedagogical expertise. Co-design reveals issues that can be addressed either through pedagogical expertise in a technically simple environment or by developing future technologies, such as interaction-enabling design. Based on the findings, it is recommended to strengthen technological self-efficacy and practice culturally diverse pedagogy, online presentation, and facilitation skills in teacher training and orientate in interactive educational technology.