- TrueCar migrated their data warehouse from an on-premises Hadoop cluster to Amazon Redshift. They load clickstream, transactions, inventory, and lead data into Redshift for analytics and reporting. - They use ETL tools like Talend and Hive to process data and load it into HDFS and S3, then load it into Redshift using a custom utility. The data is organized into schemas separating raw, user, and reporting data. - Best practices for Redshift include designing tables for compression, sort keys, and distribution, managing cluster size and workloads over time, and vacuuming and analyzing tables regularly. TrueCar's migration to Redshift improved performance and reduced costs.