There are massive differences between front-end and backend engineers. Backend engineers deal a lot less with network instability, than frontend engineers. Fro

There are massive differences between front-end and backend engineers. Backend engineers deal a lot less with network instability, than frontend engineers. Frontend engineers have multiple ways of dealing with failure. And frontend engineers have a different ways of dealing with parallel and async tasks, than backend engineers. It's not a massive challenge for a smart person to learn, but we shouldn't pretend that people don't try to apply their previous experiences to future tasks. Which is a cost, when hiring someone without specific domain experience.