This is the fourth in a series of learning briefs that explore the design, implementation and impact of Yizani Sifunde, a collaborative multi-pronged intervention designed to boost early literacy outcomes in 4- and 5-year-olds. This brief focuses on: • the changes the project made possible in early childhood development (ECD) centres, related to resources, practitioner attitudes and teaching practices, centre management, and overall ECD quality; • how durable these shifts were; and • how these shifts contributed to young children’s development. It finds that, for the participating ECD centres, the Yizani Sifunde intervention led to radically improved access to learning materials, better equipped book corners, improved confidence of practitioners with story-based literacy activities. The brief also reveals improvements in the ECD practitioners' experience of parental engagement. Areas where there was still room for improvement include emerging writing and the children's independent use of book corners remain. The brief further provides multiple sources of data revealing that the practices of the intervention have been largely sustained after project exit.