I worked with Brad for 2 years while I was at a cloud startup in Palo Alto and I really enjoyed him as a collaboration partner. He has a little design consultancy in SF, and he’s just coming off a big client project that he’s been doing for a while, so the timing might work out. He's the first person I thought of when I saw this request.
Brad was the second designer at Square early on and lead design for most of their projects for a few years. After leaving there he did stuff for Airbnb, Target, Facebook, ESPN and a bunch of other smaller startups in the bay area. I don’t think he has a website or online portfolio anywhere right now. I couldn’t find one, but you should reach out and see if something might work out.
Brad is easily one of the best people I've worked with in my startup career. He's professional, collaborative, and insightful, as well as being funny, diplomatic, and creative. He's adept at navigating difficult internal company politics with aplomb and can magically produce craft out of chaos. I keep his info in my back pocket for some of the startups I work with.
Two thumbs up.