Digital Function Outsourcing in Higher Education: Mapping the External Service Ecosystem of University Websites

University websites increasingly rely on third-party digital services to provide functions ranging from typography and analytics to accessibility, content delivery, and communication. Existing research has primarily examined such dependencies through technical measures, including network requests and external domains, providing limited insight into the functions performed by external services. This study addresses this gap by examining the functional structure of third-party service use across the websites of Polish public universities. A cross-sectional analysis was conducted on the homepages of 63 universities using network request data collected with WebPageTest. To move from infrastructural observations to functional interpretation, the study introduces the Functional Classification of External Digital Services (FCEDS) procedure, which maps external domains to digital services, service owners, and functional classes. The analysis identified 116 external domains representing 62 digital services provided by 42 organizations and covering 28 functional classes. Third-party domains were present on 96.8% of the analyzed homepages. The most prevalent functional classes were Typography (79.4%), Tag management (76.2%), and Web analytics (71.4%), while numerous other functions occurred less frequently. The distribution of service providers was also concentrated: Google services were identified on 95.2% of the websites, and the five most frequently represented service providers accounted for 63.5% of all service-provider occurrences across the analyzed websites. The findings show that technical measures of external dependencies can be complemented by information about the functions performed by third-party services. FCEDS therefore complements conventional dependency analysis by shifting attention from the number of external resources to the digital functions performed through third-party services.