IntellIJ IDEA Ctrl-click, Ctrl-Shift-F, Ctrl-U, etc, Sourcegraph when I don't know which repo or do a company-wide code search or examples.
Having a lot of tabs open for a single flow of data makes my brain forget about the start of the flow, so I put named bookmarks as I go when doing this. When debugging, the same kind of flow debugging, I use conditionnal non-suspend logging breakpoints that print out relevant stuff from variables in scope.
One of the most important parts in this is closing all tabs from time to time, and putting 2 open files side-by-side, 1440p monitor helps, or splitting part of the IDE instance into a separate window on another monitor.
This is pretty much exactly what I do now, but since I'm unfamiliar with the codebase I often find myself thinking "where was that spot where this particular data came from?" or "where was that function defined again?" and I just waste a bunch of time & mental energy trying to track it down. Couple that with the fact that this particular codebase uses JavaScript with a custom / modified module system so you can't just cmd+click to go to definition and it's a real headache. It's also exacerbated here by having LOTS of files that have very similar names (Page, PageView, BaseView, BaseViewModel, config.model, config.view are a few examples...) and these are all just under one directory for a given component, if you look there are tons of components all with the same file names, which is a pet peeve of mine, but we all have our preferences I guess. Plus go to definition is great, but sometimes you go down a path that isn't fruitful and it takes a bit to get back to where you wanted to be, and often while I'm going down a path I want to annotate parts of it so it's easier to remember what each piece is doing. Anyway, it seems like bookmarks are a pretty good solution for this in vs code (https://marketplace.visualstudio.com/items?itemName=alefragn...), I just wish I could organize the bookmarks a little bit better than just "show me them by file" or "show me then in an unordered random list".
Edit: Oh and I would normally use the debugger A LOT to trace through the code and understand the call stack and params, but another crappy thing about this project is that it generates a massive JS bundle and it crashes the app I'm testing if I try to put debugger statements in...JS ftw
