Platform business models create substantial value through engaging with a wide network of partners and complementors. The more the number and variety of such complementors, the platform has an opportunity to contribute to developing and partaking value in an ecosystem. Such ecosystems could be designed around a specific technology (like artificial intelligence), a business domain (like aviation and aerospace), or a geographic cluster (like the Silicon Valley). For these ecosystems to thrive and create value for its partners and users, there needs to be significant compatibilities and complementarities amongst its value creating partners. This chapter will elaborate and help evaluate various platform architectural models in order to create and capture value.