The danger with specialist is the focus on developer-oriented value, e.g. you're front end guy spends all his time on designing his CSS code, instead of designi

The danger with specialist is the focus on developer-oriented value, e.g. you're front end guy spends all his time on designing his CSS code, instead of designing the page. The key is whether you understand what's important for the business/product, not whether you've worked on the same stack.