Firms often establish internal product platforms to reap economies of scale and scope, and to build competitive advantage over time. The aim is to create a “stable center” on which customer adaptations and addons can be built. The same firms simultaneously strive to improve their flexibility in terms of responsiveness to change through agile practice, as adhering to external or internal change requests is an likewise and increasingly important competitive advantage. This research note is inspired by the possible tension between the two practices and aims to examine the consequences of internal product platform strategy for agile practice in an inter-organizational context. Based on interviews with innovation managers and software developers at two collaborating automotive suppliers, we suggest that there is an intricate tension between the two practices per their common strive for a balance between stability and flexibility. We also suggest that the establishment of product platforms among several actors affect their joint possibilities to respond to changes, because of the complex nested dependencies between the platforms. Ultimately, we argue that more research is needed to understand how product platform strategy and agile practices combine.