In an increasingly diverse and digital society, understanding changes in contemporary communication practices that both draw from and extend beyond traditional principles of composition serves as an apt construct for exploring the nexus among youth, literacy and technology. This article will examine instances of urban youth exchanges in digital platforms; and, within that, consider the shifting role of authorship and writing among transnational youth. Drawing data from a three-year ethnography, the focus of this article will be given to analysing digital platforms as sites social language development. As digital platforms increasingly involve "transduction" and "transformation" of text making, the multimodal means for meaning making and the social factors shaping multimodal ensembles will be highlighted. The analytic approach will combine ethnographic, multimodal and sociocultural theories, method and description for accessing digital data and environments. Findings from this study will be used to explore implications for pedagogically working with students of varied participation backgrounds and to generate curricular potentials that integrate digital tools for developing collaborative and differentiated learning environments.