A financial services group's transformation using AWS Platform Services for their cloud migration. The primary objectives were to reduce costs, improve infrastructure performance, and enhance security compliance. The financial services group achieved a significant 50% reduction in AWS Direct Connect costs and gained 360-degree visibility into infrastructure performance. This was facilitated by the use of various AWS services such as Amazon EC2, Direct Connect, Transit Gateway, VPN, S3, VPC, RDS, RAM, CloudFormation, Code Pipeline, AWS Backup, Directory Service, Workspaces, Con�gGuard, Duty, Security Hub, Lambda, CloudWatch, CloudTrail, KMS, and Certificate Manager. The cost reduction extended to the cloud spend as well, with a 28% decrease. Simultaneously, the NIST compliance adherence improved by 2x. This was achieved by implementing security baselining, following AWS best practices, on-demand creation of AMIs and CloudFormation templates, centralized security and audit log mechanisms, and the design of a scalable and highly available account structure and foundational infrastructure architecture. Security controls were implemented using S3, IAM, Access Analyzer, Service Control Policy, GuardDuty, Security Hub, AWS Con�g, and third-party tools, adhering to NIST-based security standards. End-to-end platform management was deployed, including AWS platform monitoring, patch management, configuration services, and performance baselining. To optimize managed services operations, robust tools and service management architecture were implemented. AWS subscription, billing, and resource optimization were also managed. The Transit Gateway was implemented as a centralized hub to connect more than 30+ VPCs and on-premises networks. The financial services group also implemented savings plans across more than 20 AWS accounts and configured utilization alerts to track the cloud spend. Furthermore, they enhanced their managed services operations by implementing robust tools and service management architecture. In summary, the financial services group successfully migrated to the AWS Platform Service, achieving cost savings, improved infrastructure performance, and enhanced security compliance. Key AWS services used in this transformation include Amazon EC2, Direct Connect, Transit Gateway, VPN, S3, VPC, RDS, RAM, CloudFormation, Code Pipeline, AWS Backup, Directory Service, Workspaces, Con�gGuard, Duty, Security Hub, Lambda, CloudWatch, CloudTrail, KMS, and Certificate Manager. The case study demonstrates the potential benefits of AWS Platform Service for cloud migration in the financial services sector.