Cloud Kicks (CK) increased its Salesforce development efforts so that it now has multiple custom...

Cloud Kicks (CK) increased its Salesforce development efforts so that it now has multiple custom development efforts happening in parallel. CK's developers and admins perform the custom (rations and have complained that working in one sandbox has led to many problems. They requested a solution in which they can work in at least 20 different sandboxes at once, that all start with the same base configuration and data.

What should an app builder use to solve the problem?