This document discusses Harishankar's experience scaling his company HackerRank with AWS. It describes how HackerRank started using Linode for hosting but migrated to AWS for its autoscaling capabilities. It details some migrations HackerRank made from SSHFS to S3 for file storage, from ZMQ to SQS for queuing, and from self-hosted EC2 MySQL to AWS RDS for databases to improve scalability and reliability. The document emphasizes that the migration to RDS was one of the best decisions they made as it made scaling and handling disasters much easier.