Back in the day, when you asked an engineer, "How much is 2 x 2", he'd whip out his slide rule, and reply confidently: "approximately 3.99"
Physicist: "3 is prime, 5 is prime, 7 is prime, 9 is experimental error..."
Engineer: "3 is prime, 5 is prime, 7 is prime, 9 is prime..."
(Yeah, that old joke.)
I interviewed a few years ago and the screener asked me what I have been doing lately and I said mostly vanilla JS and he wanted to know all about that framework and if I would be able to use react