A shift in primacy from online participatory cultures to algorithmic cultures invites new questions about literacies in digital contexts. This article contributes to the conceptualisation of literacies in algorithmic cultures through sociomaterial and affect theories. It develops a sociomaterial perspective that proposes felt, observable moments of user-algorithmic co-productions of culture as a needed unit of analysis for researching contemporary, critical digital literacies. It then employs this unit as a starting point for analysing the interplay of feeling, critical reflection and algorithm agency across one young adult's self-described literacy practice of 'working algorithms' across social media platforms. Analysis illustrates how critical literacies in algorithmic cultures are driven by processes of human-machine feeling-thinking that cannot be reduced to rational critiques of ideologies, platform capitalism or other forms of power alone. It describes how Malaya became more attuned over time to the affects of working with platform algorithms to craft her community, her sense of self and her sense of well-being. This sensitivity to feeling moved and feeling the capacity to move machines through the use of her literacies highlights how the facilitation of affect is a crucial point of analysis in understanding contemporary digital literacies.