I tend to only use concerns in extremely cut-and-dry cases. And even then, I sometimes get annoyed with them when hunting for that one method which is tucked aw

I tend to only use concerns in extremely cut-and-dry cases. And even then, I sometimes get annoyed with them when hunting for that one method which is tucked away in a concern somewhere. But sometimes they are the best solution for making sure a bit of shared behavior doesn't get out of sync between models.