The advent of cloud computing has revolutionized the way enterprise systems are managed and integrated, particularly in the context of legacy systems like PeopleSoft. As organizations continue to migrate towards cloud-based ecosystems, the process of modernizing their PeopleSoft applications to Oracle Cloud presents both significant challenges and immense opportunities. This paper presents a comprehensive guide for system modernization, focusing on the conversion of PeopleSoft applications into Oracle Cloud, with an emphasis on functional components and workflow changes. The research integrates technical insights from key case studies and theoretical frameworks on cloud migration and digital transformation. Through a detailed examination of the steps involved in the modernization process, the paper highlights the challenges of maintaining functionality, optimizing workflows, and ensuring seamless integration within the Oracle Cloud environment. By leveraging the concept of digital twins, service-oriented applications, and the key tenets of cloud adoption, this paper provides actionable recommendations for businesses seeking to streamline their PeopleSoft to Oracle Cloud transition. Additionally, it explores the strategic impact of this transformation on organizational efficiency, data management, and scalability. The study incorporates lessons learned from existing research on digital ecosystems and workflow models, offering a theoretical basis for effective implementation. This research contributes to the field by providing both a conceptual and practical roadmap for organizations embarking on cloud-based system modernization.