GitHub.com, initially built on Ruby on Rails with a single MySQL database, has evolved over the years to support its growth and resilience demands by iterating its database architecture. Originally relying on a primary database cluster named mysql1, GitHub faced scalability challenges as it expanded. In response, the company implemented virtual partitions and schema domains to manage data more effectively, enforced by SQL linters that ensure data can be safely partitioned without cross-domain queries. In addition, GitHub developed a transaction linter and employed tools like Vitess and a custom write-cutover process for moving large data sets across database clusters without downtime. These efforts have resulted in a 50% load reduction on database hosts, improved system reliability, and a reduction in database-related incidents. The strategic use of both vertical and horizontal partitioning has allowed GitHub to accommodate sustainable growth, with plans to detail further advancements in future communications.