The thing is brilliant UI engineers will stun you with incredible UI. It's almost like not investing in AI, you will get blind sided by products that just look and feel better. Your backend engineers are never going to cut it. This is true for backend engineers too, if you try half ass it with "full stack" devs, brilliant backend devs will stun you with things and your products will be inferior.

For example, we all got stunned by the machine learning people. We have to pay attention to everyone.