Intuit has an "all in" strategy in adopting the AWS cloud. We have already moved some large workloads supporting some of our flagship products (TurboTax, Mint) and are expecting to launch hundreds of services in AWS over the coming years. To provide maximum flexibility for product teams to iterate on their services, as well as provide isolation of individual accounts from logical errors or malicious actions, Intuit is deploying every application into its own account and virtual private cloud (VPC). This talk discusses both the benefits and challenges of designing to run across hundreds or thousands of VPCs within an enterprise. We discuss the limitations of connectivity, sharing data, strategies for IAM access across account, and other nuances to keep in mind as you design your organizations migration strategy. We share our design patterns that can help guide your team in developing a plan for your AWS migration. This talk is helpful for anyone who is planning or in the process of moving a large enterprise to AWS with the difficult decisions and tradeoffs in structuring your deployment.