> This approach probably works well because I know how things work at a high level; I think it would be disastrous to do this without any real understanding.
I actually interview for this skill specifically. I stress to candidates that they can and should search the web in whatever way they would when tasked with code in real life.
The speed at which someone can process search results and stackoverflow responses to filter out crap and find the solution is the best proxy I've found for developer productivity.
Some people don't search for anything, even after prodding them 3 times that it's 100% fine to search and they definitely won't lose points. They still won't do it, because it's just not how they reason about problems.
Other candidates will immediately identify the problem, search with good queries, quickly navigate through a bunch of sites, find the relevant info, copy/paste, and solve the challenge.