Innovation is a cumulative process in which past knowledge created by others can be both a source for predictable outcomes and also a barrier to significant change. The recent literature on digital innovation suggests that open platforms, which encourage their developers to build upon each other’s knowledge when innovating their add-on apps in the periphery, face a related paradox. Developers face the tension of either being coherent with the past, or flexible to adjust to the future. In this paper, we examine how the trade-off between coherent and flexible search mechanisms affects the individual developer’s choice of innovating a certain app as well as his or her cumulative impact, i.e., the degree of modifications to the app. We study an open platform in the multi-disciplinary field of nanotechnology, in which 480 developers perform more than 30,000 problem-solving actions over a period of 10 years. We use relational event modeling to differentially assess the effect of the coherent and flexible search strategies. We find that developers are significantly more likely to choose a certain app that is consistent with both a coherent and flexible strategy. However, a coherent strategy leads to greater cumulative impact on an app compared to a strategy of being mutually coherent and flexible. Thus, our findings indicate both a complementary and a contradictory logic in how the tension between coherence and flexibility unfolds. We make contributions to the recent literature on digital innovation as well as the innovation literature more broadly. Further, our results inform innovation policy and platform design.