Great point here: "I go through periods of self-doubt about my qualifications as a web developer. I have a sense I’m not alone in this. Our field is by nature

Great point here: "I go through periods of self-doubt about my qualifications as a web developer. I have a sense I’m not alone in this. Our field is by nature a generalists’ field, where expertise involves synthesis of concepts and technologies, not complete mastery of a single, static topic. It’s hard to know how to tell if you’re good at your job." I'd say, I'd agree fully but you can look at it as an advantageous position, in my opinion. The ability to bend a lot of different concepts/technologies that were put together by experts into something that solves the problem puts you in an important place. I'd say show love for the open source community and the people who know everything about a particular framework or technology, but really it comes down to asking, "No, not familiar, what are the advantages of this [new thing] over what we've been doing?"