A crucial part of data-driven ecosystems1 is the management and processing of complex data structures, as well as the proper handling of the data flows within the ecosystem. To manage these data flows, data-driven ecosystems need high levels of interoperability, as it allows the collaboration and independence of both internal and external components. REST APIs are a common solution to achieve interoperability, but sometimes they lack flexibility and performance. The arising of GraphQL APIs as a flexible, fast and stable protocol for data fetching makes it an interesting approach for data-intensive and complex data-driven (eco)systems. This paper outlines the GraphQL protocol and the benefits derived from its use, as well as it presents a case of study of the improvement experienced by the Observatory of Employment and Employability (also known as OEEU) ecosystem after including GraphQL as main API in several components. The results of the paper show promising improvements regarding the flexibility, maintainability and performance, among other benefits.