This article concludes a longitudinal study with the broader aim to explore learner development as a long-term, social process. One goal has been to inform the endeavours of improving student engagement, retention, as well as under-representation of certain demographics in computing. Students of two computer science-related study programmes (CS/IT) reflected on their engagement in their field of study at different times during the first three study years. Drawing on social identity theory, the focus has been to analyse and describe different ways in which the students experience participation in CS/IT, i.e., doing, thinking, and feeling, in relation to CS/IT, negotiated among different people. Insights into participation in CS/IT were used to discuss what it entails to fit in and become a computing professional. Phenomenographic analysis yields an outcome space that describes increasingly broad ways in which first-, second-, and third-year students experience participation in CS/IT. Two further outcome spaces provide nuanced insights into experiences that are of increasing relevance as the students advance in their studies, participation as problem solving, and problem solving for others. Participation as problem solving appears to be central in this learning environment and the students integrate such experiences into their histories of engagement in CS/IT. In study year 3, the students also reason about participation as problem solving for others that they encounter in the human computer interaction course. However, at that time several students perform a technical problem solver identity and reject such broader ways of participating in CS/IT.