It's a strange experience. DuckDuckGo pride themselves on radical transparency, but they cannot commit to this in the interview process. I got through to the first take-home exercise, and my recruiter said that they'd set up a meeting to discuss it, but they didn't. I was advised to keep it brief and not too technical. The test was rejected, which is fine, but given how strongly they sell transparency, it's very incongruous that they can't even give a brief explanation. I know they say that this is their policy, but if you give up your transparency at the first challenge, then it's probably not a value that you hold true.