Context: The explosive growth of renowned software ecosystems such as the cloud-based accounting platform Xero, and the communication hub Slack has largely occurred because of an app marketplace they have built. To a large extent, in-app marketplaces are becoming mandatory for SaaS companies. Looking at the 15 largest SaaS companies, all of them have an app marketplace with a median number of 347 applications integrated to the marketplace [1]. It is challenging for any organization to orchestrate a platform independently. The more other participants contribute to that platform, greater resources are applied to create richer offerings for the platform’s end-users. Looking at the initial stages of when an organization transitions from a product to platform development, there is an underlying challenge of how that organization attracts third-party developers to partner and enrich the ecosystem. Objective: This thesis aims to identify what can be used to attract third-party developers or organizations to develop and integrate onto an emerging platform or- ganization. It also examines problem areas faced by emerging software ecosystems when trying to attract third-party developers onto their platform. Method: I performed a case study to investigate the needs of third-party devel- opers looking to develop on a platform organization. I also used mixed data collection to obtain different sources of information, including internal and external interviews, virtual events, an internal developer workshop, and an investigation of competitors and other software ecosystems. Results: The thesis highlights that emerging software ecosystems often do not have the resources or capacity to build an initial robust platform experience as some of the more established software ecosystems like HubSpot and Shopify. With the lack of research completed to date on emerging software ecosystems, I was motivated to investigate the best practices that are crucial to attract third-party developers onto the platform. Conclusion: Through thematic analysis, the study revealed eight emerging con- cepts. When transitioning to a software ecosystem, organizations have struggled with six common issues. Additionally, six recommendations were gathered to help guide emerging software ecosystems towards best practices to attract third-party developers onto their platform. / Graduate