Hi, friend of mine asked me to help with a project. They use Segment.io and want to fully migrate to GTM, but they do make frequent updates. Migration will take me a while, so how do I make this efficiently? Do I need to duplicate a theme and work on it separately and then publish when it is ready? Also is it possible to run a testing store? or I must run preview every time to check my changes?
Any help and suggestions will be appreciated. Thanks in advance.