This study provides a better understanding of how the application of collaborative soft-ware development techniques is shaped by and shapes the transactive memory systems of information systems development teams. In particular, we draw from results of critical realist case studies on development teams that apply pair programming and peer code re-view. The findings improve our understanding of how teams vary in the way they apply these collaborative quality assurance techniques and how their application is theoretically linked to a team’s transactive memory system, as well as the properties of the technolo-gies the techniques rely on. This study replies to recent calls to study socio-cognitive im-plications of software development techniques. It contributes to previous work on quality assurance techniques by being among the first to empirically study effects that go beyond error correction. This also adds substance to the discussion if different techniques com-plement or substitute each other.