The company Contentful introduced a new feature called copy-on-write, which improves environment cloning by reducing I/O requirements and eliminating page noise. The previous approach of physically copying all records in an environment was resource-intensive and caused performance issues. By using copy-on-write, only shared records are copied when changed, saving I/O and CPU time. The implementation required several steps, including preparing the database schema, modifying SQL queries, identifying unique content, and demonstrating that the new solution didn't open the door to data races. The rollout was done online without downtime for customers, but it involved some write downtime in certain cases. The feature has improved environment cloning by 50 times, making it faster and more efficient.