The interview was 30 mins on the phone with one of the senior engineers, followed by about 5 hours onsite. All went great via the phone, got called in, aced it with 4 engineers. Then spoke with a Dir (went good from my point of view). The recruiter emailed me that they gave all thumbs up. The final talk with a CTO who was previously on vacation. Met him for an hour, they promised to get back to me within about a week. Today I got an email from the recruiter that they declined, "not enough machine learning experience" (I got 3.5 years of practical success)... I've heard from some of the engs that their process is slow, many good candidates didn't make it due to that. Even though I was not shocked to get shot down, I attribute this twist on the CTO 100%. I was kind of warned of that by some engs, that he is not an easy one for many reasons. Overall, while the place looked OK, it felt empty, not vibrant, and given they have some serious competition from RocketFuel and others I wouldn't bet my house on it.