Palo Alto: Machine Learning Engineers, Java Engineers, (Big) Data Engineers (I feel like without "big" regular data nowadays just looks lonely)
Diffbot (www.diffbot.com) is brute-force building the semantic web via computer vision, machine learning, NLP, and other buzzwords that aren't actually buzzwords for us. Moreover we're doing it by offering real API services to real developers, and earning real money.
Well funded, making excellent revenue, working on challenging novel stuff. Check out our jobs at www.diffbot.com/company (and play with our APIs first to know what we're all about!).
Ask HN: Who Is Hiring? (November 2012)