CumulusCI is a developer-focused command-line tool for developing Salesforce packages. Like SFDX, it’s generally not something declarative admins would use—it's way over my head! But CCI has a set of functions for storing a dataset with relationships intact and then allowing you to push that data into a sandbox. By learning a bit about its file structure and a few important commands (and making a cheat sheet to remember them) I am able to build and store test datasets that look like real data. Now whenever I create a new sandbox I can fill it with data for testing and training in just moments. Let me show you how you can also take advantage of this powerful and free tool.