Got ghosted after a full onsite loop and asked for feedback anyway, actually got a real answer

Five rounds, half a day, then two weeks of nothing. Assumed asking for feedback after a rejection like that was pointless, recruiters usually give a generic line. Asked anyway, framed it as wanting to improve rather than fighting the decision, and got a specific note about a system design tradeoff I'd missed. Didn't get the job, but that one piece of feedback fixed the exact gap in my next two interviews.