Amazon.com migrated its enterprise data warehouse-hundreds of thousands of daily jobs running in one of the world's largest Oracle data warehouses-to a scalable, AWS-based data lake in less than two years. In this session, we dive into the architecture of Amazon.com's data lake and how it leveraged Amazon Redshift and Amazon EMR. We also review the key strategies used to migrate all of the legacy jobs to the new system, and we include lessons learned from the first year of running the system at scale after the migration.