API Management Patterns for Public, Partner, and Group Web API Initiatives with a Focus on Collaboration

API management of public, partner, and group Web APIs (APIs) is an organizational function at the interface between several stakeholders inside and outside of an organization. Most current API management literature is concerned with technical aspects of API management. Therefore, we use a design science approach to identify API management stakeholders, pattern candidates, and patterns focusing on collaboration. We derive these results from 16 expert interviews with API management team members, mainly working at established and SME organizations in Europe. The pattern's target audience are API provider team members. The purpose of this paper is to describe the design approach, the two exemplary patterns "Role-based marketing"and "Frontend venture", and six overarching observations made during the pattern language design. The first observation is that API provider teams usually control the resources used to collaborate with API consumers. Nevertheless, consumers want personal contact and contractual agreements before integrating an API. Also, most API management concerns are related to the API consumer. Then again, few standardized approaches for collaboration with backend functionality providers, legal or marketing exist. Additionally, an API has its own lifecycle. Finally, the strategic relevance of the API resources and the API consumers' organizational structure influence a patterns' suitability.