Entrepreneurs are indispensable to our society. They translate innovative ideas into valuable products and services which in several cases also contribute to a more sustainable, convenient, and ethical world. Moreover, entrepreneurship is one of the most significant drivers of economic growth in a particular area. The entrepreneurship literature has shown that entrepreneurs are usually highly dependent on the environment in which they arise. Some sites show higher entrepreneurial activities than others, which is often due to the available resources and the interconnectedness between the involved actors in these areas. To comprehend the complex nature of these business environments, the term ‘Entrepreneurial ecosystem’ (EE) emerged, which systematically looks at the resources and interconnections between actors at a certain place. A successful EE is perceived as an area in which ventures cultivate and grow. Previous studies which explored how these EE emerge, particularly focussed on how public authorities position themselves. On the contrary, this research aims to shed light on the role of a private developer in shaping an EE. The data of this study is collected by reviewing the literature about EEs and the influence of private developers. This literature review formed the academic foundation of this study. Afterward, 16 in-depth expert interviews were conducted. Subsequently, the data from the interviews were thematically coded and analysed using Atlas.ti. Ultimately, comparison and discussion between the literature review and the interviews are conducted. The findings of this study indicate that developers exert their influence in different ways. First of all, they develop meeting places, to stimulate encounters. Secondly, they offer flexibility in terms of space to respond to the growth of the companies. And thirdly, they develop spaces that can be shared by multiple companies. Aside from these three physical design principles developers adopt in shaping the built environment, they also exert their influence in selecting certain end-users. The results demonstrate that putting a cluster of start- and scaleups, a small share of established companies, and academia closely together empowers the overall EE. Furthermore, a key takeaway is that developing an ecosystem goes beyond developing real estate. Needless to say, facilitating the needs of entrepreneurs supports them in growth. These needs are not only accommodation-related but also cover soft services (e.g, organizing events). Next, these needs also continuously change. This implies that a developer should be adaptable to quickly respond to these fast-changing needs. Over and above that, they could participate in the operations phase to ensure that they transfer the developed buildings whenever not solely the real estate, but the actual EE is finished. Evidently, this is not the core business of developers. Therefore, they could team up and invest in a collaboration with another party that is more specialized in real estate operations and soft service provision. Overall, this study added a chunk of new information to the existing body of knowledge about EEs. It shed light on what role and responsibilities of a private developer, and what influence they exert, and could exert in shaping an EE.