Governments and organizations in both public and private sector are operating in fields of ever-growing uncertainty and complexity. To study this complex environment, the concept of ecosystems has been suggested, interpreting organizations as intertwined systems among layers of evolving ecosystems. While offering possibilities, operating in an ecosystemic environment might prove to be challenging, and the change from traditional governance structures might be difficult to manage, requiring holistic yet detailed view. Enterprise Architecture (EA) has been an interest of academics and practitioners for few decades, offering one of the most prominent solutions to managing complex organizations. Recently, it has been discussed that EA should further evolve to respond to the interconnectedness of organizations’, thus extending the focus of enterprise architecting from intra-organizational to the ecosystems level. Based on data from 26 in-depth practitioner interviews in Finland, we discuss how EA should be developed to better support Finnish public sector ecosystems. Our data indicates that qualities such as organizational capabilities, holistic view, co-creation and needs-based utilization are essential features of public sector ecosystem EA.