I have, and it sucks. When I was young, I'd get hired to do things I'd never even done before, because, "you're smart, and you'll figure it out." And I was sma

I have, and it sucks. When I was young, I'd get hired to do things I'd never even done before, because, "you're smart, and you'll figure it out." And I was smart, and I did figure it out. Yay. When I became old, I'd only get hired if 1) I had generated explicit expertise in the area they were hiring for, and I could prove it, or 2) I was being hired by someone I worked with 20 years earlier who remembered me and that I was smart and could figure things out. So the advice is: 1) go back in time and generate a huge network of people who can testify as to your general competence, they will help you keep making a living for decades to come or, 2) (if no time machine available) pick ONE thing, read everything you can about it and and practice it, and become an expert, so you can pass the interview in today's world. As a good generalist, you can learn new things fast. But you'll have to do the learning before you get hired, not after.