I went from Ruby to JavaScript development. First, I’d like to say I think starting with Ruby/Rails is a bad idea. Ruby uses a lot of higher order functions, but it isn’t super clear from the syntax how that all works. Higher order functions in JS are much more clear, IMO, on account of having to use parens to call the function (in Ruby, you don’t need parens to call function, you can just name the function and delineate the arguments with spaces).

So with Ruby, I was just pattern matching—I never had an intuition of what lambdas were doing until I moved over to JS.

The Feynman Method was another aha moment. Learning how to learn, in my case, by writing down stuff in my own words as if I were teaching someone else was probably the most important thing. That helped me develop a much deeper understanding of important concepts.

Similarly, not trying to learn everything was a big deal. Don’t try to learn all the niche technologies you see in job listings expecting you need to know those things in order to qualify for the position. If you just do dozens of tutorials, you’ll end up knowing a lot of things very superficially. It’s much better to know a handful of ubiquitous, related technologies very well and have a strong foundation of programming fundamentals. Those things can transfer over to other technologies, when you need to pick them up.