The article mentioned ctags, which actually gets you quite far in this regard. Combined with CtrlP (a vim plugin) and the Silver Searcher, I navigate large codebases quite quickly. I do agree that full blown IDEs probably have better support for refactoring code, but so far the advantages of using vim/tmux/unix commands are much more valuable to me:

- it's more natural for me to have a shell as a starting point and jump into an editor, rather than the other way around; it suits my workflow much better

- I can combine tools in a very convenient way, `:!ls /tmp` real quick from my vim, fuzzy search some json file hidden inside an atrocious directory structure, `:!git status -s` to see what I've changed, and so on

- IDEs are often language specific, which implies learning a new IDE for every language; I only need to know vim, which I use for every language I use but Java

- I'm more of a keyboard person rather than a mouse person, so terminal based tools that have intuitive keyboard bindings suit me better than IDEs which often require you to learn some really awkward key combinations to do things that I do very quickly in vim; just take a look at the cheatsheets for e.g. PyCharm/IntelliJ and you'll see what I mean (yes I know about the vim plugin for IntelliJ, but as an experienced vim user, it's not that great)