This research paper presents an initial attempt to introduce and explain the emergence of new phenomenon, which we refer to as platform constellations. Functioning as highly modular systems, the platform constellations are collections of highly connected platforms which co-exist in parallel and as such allow us to study platforms not only as separate entities, but also to investigate the relationship between several platforms offered and governed by one and the same platform provider. By investigating two case studies of indigenous platform constellations formed around the hugely popular instant messaging apps KakaoTalk and LINE, we are able to gain valuable insights about the nature of these new constructions and to capture and synthesize their main characteristics in a framework. Our results show that platform constellations possess unique innovative capabilities, which can improve users’ acquisition and users’ engagement rates as well as unlock new sources of value creation and diversify revenue streams.