Earlier quoted context omitted.
Once you have a strong understanding of how to architect code and how the "big picture" technologies fundamentally work, learning the different flavors/frameworks/etc takes time, but we're talking weeks of learning vs the years it takes to understand the fundamentals. You're not going to be an expert in the idiosyncrasies of X tech unless you are working with it full time for a year or so but you'll know enough to pa…
but you'll know enough to pass a job interview. Unfortunately not. I believed it myself, until it became obvious it was a myth: One interview went like this: They sat me down, opened up postgres, and said "Accomplish these goals." The goals were simple things like write SQL statements to query for certain types of users, or join data together. I never had any reason to learn any of that. I knew that I could learn it…
You could spend nights and weekends learning postgresql/SQL, web MVC architecture, JS syntax (for node.js and frontend dev work), and http concepts, in a few months. That's enough to open a lot of interview doors.