Alluxio is a virtual distributed file system that serves as a data access layer between applications and storage systems. It provides a unified interface, improved performance through caching, and enables transparent migration between storage systems. Alluxio deployed with Presto on cloud storage like S3 can provide 5x faster query performance through caching query data in Alluxio workers located with compute. Case studies show how Alluxio improved response times for analytics workloads at large companies by eliminating remote data access and enabling data locality.