The crux of the article is this: "Do they believe they have familiarity with different layers, or true mastery?" Full-stack guys never (that I have seen) have

The crux of the article is this: "Do they believe they have familiarity with different layers, or true mastery?" Full-stack guys never (that I have seen) have mastery of all layers, but rather can perform at a reasonable level at all necessary layers to make an app happen. They might have mastery of a few layers, they might lean on infrastructure like herokou to cut out a section of the stack, whatever, but they can get it done. They are also always scary smart, and scary employable.