"One of the marks of a professional programmer is knowing how to organize software so that the complexity remains manageable as the size increases. Even among professionals there are large differences in ability. The programmers who can effectively manage 100,000-line projects are in a different league than those who can manage 10,000-line projects. ... Writing large buggy programs is hard. ... Writing large correct programs is much harder."
Jeff Atwood's metrics will help you filter out engineers whose complexity ceiling is <1k lines -- StackOverflow answers, whoopee -- but that's not a terribly hard thing to interview for. Much harder to interview for the very best, the mythical 10x productivity programmers[2], those who can handle 100k LOC, 1M, or more. Perhaps this is the difference between an experienced non-expert and a real expert[3].
In my experience not a lot of employers care about this, perhaps because their challenges aren't those of complexity-in-scale, or perhaps because complexity hasn't bit them hard enough yet, or perhaps because they are "unconsciously incompetent"[4]. About the only hiring signal I've identified for this is interest in functional programming -- languages like Clojure and Scala exist precisely to raise the ceiling of complexity a human can handle[6] -- and as such I'm trying to learn this stuff and trying to find people via the community who care to hire engineers with these skills. Unfortunately my own bias may be blinding me, you never know which side of Dunning-Kruger[5] you're on until it's too late.
If you care about these things: I'd love to know who you are and what you're working on, email me.
[1] http://www.johndcook.com/blog/2008/09/19/writes-large-correc... [2] I am not one of these, but I strive to be one someday. [3] http://www.dustingetz.com/how-to-become-an-expert-swegr [4] http://en.wikipedia.org/wiki/Four_stages_of_competence [5] http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect [6] Clojure creator Rich Hickey talking about complexity: http://www.infoq.com/presentations/Simple-Made-Easy
edit: man, this got 2 downvotes in 2 minutes, cmon guys i put a lot of thought into this!