East African governments cannot train enough secondary teachers if every candidate must leave a classroom for a residential year. This paper evaluates a two-year, in-post postgraduate education pathway at The University of Edinburgh with teaching practice observed by video and local mentors. Among 210 practising teachers in Kenya, Uganda and Tanzania, classroom observation scores improved on questioning and assessment for learning. Attrition was highest among teachers with no smartphone storage for lesson recordings. A low-cost offline packet of lesson clips, distributed by school clusters, cut that attrition by half in a nested trial. The finding for AFU is that a continental education faculty must partner with school clusters, not only with individual applicants. Quality is protected when mentors are trained and paid, and when the university refuses to mark a portfolio that has no evidence of pupils’ work. Digital teacher education is not a shortcut around practice. It is a way to keep practice in the school that already needs the teacher.