The financial industry has been significantly transformed by innovations, but traditional banks have managed to maintain their dominant position without implementing many innovations. However, new technologies have caused a shift and should no longer be ignored. Financial institutions are now facing competition from high-tech newcomers, also known as Fin- or BigTechs, that threaten their dominance. A recent study shows that financial institutions have a growing interest in (cloud) platform business models (Fintechs) without being handled in a responsible way. Firms are under pressure to transform, but guidance on how to design and control this transformation is hard to find. EU regulators are concerned about the speed and scale at which financial institutions are moving critical functions and market operations to a few cloud platforms and will soon have to demonstrate their ability to recover from a cyber-attack. Choosing a secure cloud platform is essential, but the complexity, risks and regulation make this decision-making process challenging. This study aims to identify the key factors influencing the adoption of cloud platforms within the Dutch financial sector and determine the most suitable Cloud platform for this sector. Based on the knowledge gap and the aim of this research, the following main research question was formulated: What are the key influencing factors that determine the adoption of a cloud platform within the cloud platform battle within the Dutch financial sector? The study uses a qualitative approach and the Best-Worst Method to determine the key factors and the most suitable cloud platform. As the focus is on standard selection, a modified version of van der Kaa's 2011 framework was eventually chosen to identify the most important factors in this battle. From the 29 factors in the framework, the 24 most relevant were selected and five additional specific Cloud platform factors were added. This resulted in a new set of 29 factors relevant to Cloud platform adoption. Data is collected through literature review and expert interviews. Interviews were conducted with 13 IT/Cloud experts from various Dutch financial institutions, varying from the consulting, banking, insurance, government and academic sectors. Ultimately, this research showed that the factors: 1) Security & privacy, 2) Brand reputation and credibility, 3) Pricing strategy, 4) Commitment and 5) Compatibility, are the key influencing factors determining the adoption of a cloud platform within the cloud platform battle within the Dutch financial sector. Based on these key factors and the platform comparison, it was found that among the three most dominant cloud platforms (Amazon Web Services (AWS), Microsoft Azure, and Google Cloud), Microsoft Azure is currently the most suitable cloud platform for the Dutch financial sector.