For years I have been peeved by how external search engines, in particular DuckDuckGo and Google, are often able to find better, even much better, matching questions on StackOverflow than the internal question search. (And I'm assuming the situation is similar on other network sites, hence the post here.) This is still the case today.
Case in point: Searching for ways to iterate over a simple range of integers in C++. There is one "canonical" question about this on SO.
With internal search:
we fail to find that question and its answers - even on the second page of results and probably at all; but with external search:
the top result is the appropriate question.
Naturally, if you know the exact title of the question you have better luck with SE's internal search tool:
I would like to ask that more effort be invested in improving search efficacy.
More specifically, I suspect that part of the problem is the difficulty of accounting for concept closeness, or near-synonimity: "looping" vs "iteration", since if we just switch those two words in the example above we get what we want.