This paper is based on a living lab project, which is an open, user-centric, innovation approach, where several actors from industry, user groups and academia are involved. The research question is: How can interaction dynamics be understood in a living lab innovation process? We applied an action-oriented research approach, where the empirical results are from The Find Project (TFP), which aim is to customize an ICT product based on the needs of a user group. The findings are analyzed from a community of practice perspective where three different communities, i) researchers from Halmstad Living Lab (HLL), ii) ICT developers (ICTD) and iii) next of kin of demented elderly persons (NOKD), represented the unit of analysis. We identified situations and activities that played a vital role for the innovation process in terms of boundary interaction dynamics. The contribution of our research to innovation theory is a combination and further exploration of the boundary spanning and communities of practice theories. We have developed a conceptual model describing the dynamics in boundary interactions of an ICT innovation process with regard to boundary objects-inuse and brokering. The conceptual model highlights two different levels of brokering: i) inner-level brokering and ii) outer-level brokering.